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Publisher: Elsevier   (Total: 3184 journals)

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Showing 1 - 200 of 3184 Journals sorted alphabetically
Academic Pediatrics     Hybrid Journal   (Followers: 37, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 25, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 100, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 27, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 37, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 5)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 7)
Acta Astronautica     Hybrid Journal   (Followers: 430, SJR: 0.758, CiteScore: 2)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 28, SJR: 1.967, CiteScore: 7)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 3)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 10, SJR: 0.18, CiteScore: 1)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 293, SJR: 3.263, CiteScore: 6)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 6, SJR: 0.504, CiteScore: 1)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.542, CiteScore: 1)
Acta Oecologica     Hybrid Journal   (Followers: 12, SJR: 0.834, CiteScore: 2)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.307, CiteScore: 0)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 1, SJR: 1.793, CiteScore: 6)
Acta Poética     Open Access   (Followers: 4, SJR: 0.101, CiteScore: 0)
Acta Psychologica     Hybrid Journal   (Followers: 26, SJR: 1.331, CiteScore: 2)
Acta Sociológica     Open Access   (Followers: 1)
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.052, CiteScore: 2)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 3, SJR: 0.374, CiteScore: 1)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 2)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.344, CiteScore: 1)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 1)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 7, SJR: 0.19, CiteScore: 0)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 8)
Acute Pain     Full-text available via subscription   (Followers: 15, SJR: 2.671, CiteScore: 5)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.53, CiteScore: 4)
Addictive Behaviors     Hybrid Journal   (Followers: 17, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 9, SJR: 0.755, CiteScore: 2)
Additive Manufacturing     Hybrid Journal   (Followers: 11, SJR: 2.611, CiteScore: 8)
Additives for Polymers     Full-text available via subscription   (Followers: 23)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 180, SJR: 4.09, CiteScore: 13)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 12, SJR: 1.167, CiteScore: 4)
Advanced Powder Technology     Hybrid Journal   (Followers: 17, SJR: 0.694, CiteScore: 3)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.277, CiteScore: 1)
Advances in Agronomy     Full-text available via subscription   (Followers: 16, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 28, SJR: 0.126, CiteScore: 0)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 11, SJR: 0.992, CiteScore: 1)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 11, SJR: 1.551, CiteScore: 4)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 24, SJR: 2.089, CiteScore: 5)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 15, SJR: 0.572, CiteScore: 2)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.61, CiteScore: 7)
Advances in Botanical Research     Full-text available via subscription   (Followers: 2, SJR: 0.686, CiteScore: 2)
Advances in Cancer Research     Full-text available via subscription   (Followers: 32, SJR: 3.043, CiteScore: 6)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 1.453, CiteScore: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 1.992, CiteScore: 5)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 5)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 14)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 28, SJR: 0.156, CiteScore: 1)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.713, CiteScore: 1)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 10, SJR: 1.316, CiteScore: 2)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 26, SJR: 1.562, CiteScore: 3)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20, SJR: 1.977, CiteScore: 8)
Advances in Computers     Full-text available via subscription   (Followers: 14, SJR: 0.205, CiteScore: 1)
Advances in Dermatology     Full-text available via subscription   (Followers: 15)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 13)
Advances in Digestive Medicine     Open Access   (Followers: 11)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Ecological Research     Full-text available via subscription   (Followers: 43, SJR: 2.524, CiteScore: 4)
Advances in Engineering Software     Hybrid Journal   (Followers: 29, SJR: 1.159, CiteScore: 4)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 8)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 49, SJR: 5.39, CiteScore: 8)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 1)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 62, SJR: 0.591, CiteScore: 2)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Genetics     Full-text available via subscription   (Followers: 20, SJR: 1.354, CiteScore: 4)
Advances in Genome Biology     Full-text available via subscription   (Followers: 10, SJR: 12.74, CiteScore: 13)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 24, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 12, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 23)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 3, SJR: 0.193, CiteScore: 0)
Advances in Immunology     Full-text available via subscription   (Followers: 36, SJR: 4.433, CiteScore: 6)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 10, SJR: 1.163, CiteScore: 2)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 2, SJR: 1.938, CiteScore: 3)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6, SJR: 0.176, CiteScore: 0)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 3)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.682, CiteScore: 2)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Marine Biology     Full-text available via subscription   (Followers: 20, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 12, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 7, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 23)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 8)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.182, CiteScore: 0)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 4)
Advances in Oncobiology     Full-text available via subscription   (Followers: 2)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 17, SJR: 1.875, CiteScore: 4)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.174, CiteScore: 0)
Advances in Parasitology     Full-text available via subscription   (Followers: 5, SJR: 1.579, CiteScore: 4)
Advances in Pediatrics     Full-text available via subscription   (Followers: 25, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 17)
Advances in Pharmacology     Full-text available via subscription   (Followers: 16, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.574, CiteScore: 1)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.109, CiteScore: 1)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 10)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20, SJR: 0.791, CiteScore: 2)
Advances in Psychology     Full-text available via subscription   (Followers: 65)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.371, CiteScore: 1)
Advances in Radiation Oncology     Open Access   (Followers: 1, SJR: 0.263, CiteScore: 1)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.101, CiteScore: 0)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 6)
Advances in Space Research     Full-text available via subscription   (Followers: 414, SJR: 0.569, CiteScore: 2)
Advances in Structural Biology     Full-text available via subscription   (Followers: 5)
Advances in Surgery     Full-text available via subscription   (Followers: 13, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 36, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 20)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 15)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 51, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 365, SJR: 0.796, CiteScore: 3)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.42, CiteScore: 2)
African J. of Emergency Medicine     Open Access   (Followers: 6, SJR: 0.296, CiteScore: 0)
Ageing Research Reviews     Hybrid Journal   (Followers: 11, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 468, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (Followers: 1, SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 17, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 44, SJR: 1.272, CiteScore: 3)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 4)
Agriculture and Natural Resources     Open Access   (Followers: 3)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 58, SJR: 1.747, CiteScore: 4)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.589, CiteScore: 3)
Air Medical J.     Hybrid Journal   (Followers: 6, SJR: 0.26, CiteScore: 0)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.19, CiteScore: 0)
Alcohol     Hybrid Journal   (Followers: 12, SJR: 1.153, CiteScore: 3)
Alcoholism and Drug Addiction     Open Access   (Followers: 11)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 2, SJR: 0.604, CiteScore: 3)
Alexandria J. of Medicine     Open Access   (Followers: 1, SJR: 0.191, CiteScore: 1)
Algal Research     Partially Free   (Followers: 11, SJR: 1.142, CiteScore: 4)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.504, CiteScore: 1)
Allergology Intl.     Open Access   (Followers: 5, SJR: 1.148, CiteScore: 2)
Alpha Omegan     Full-text available via subscription   (SJR: 3.521, CiteScore: 6)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 10, SJR: 0.201, CiteScore: 1)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 53, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 5, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 5, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 6)
American Heart J.     Hybrid Journal   (Followers: 57, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 62, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 45, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 11)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 13, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 34, SJR: 7.45, CiteScore: 8)
American J. of Infection Control     Hybrid Journal   (Followers: 29, SJR: 1.062, CiteScore: 2)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 35, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 49)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3, SJR: 1.967, CiteScore: 2)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 234, SJR: 2.7, CiteScore: 4)
American J. of Ophthalmology     Hybrid Journal   (Followers: 66, SJR: 3.184, CiteScore: 4)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 5, SJR: 0.265, CiteScore: 0)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.289, CiteScore: 1)
American J. of Otolaryngology     Hybrid Journal   (Followers: 25, SJR: 0.59, CiteScore: 1)
American J. of Pathology     Hybrid Journal   (Followers: 30, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 28, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 39, SJR: 1.141, CiteScore: 2)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.767, CiteScore: 1)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 7)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.144, CiteScore: 3)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 63, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 20, SJR: 0.411, CiteScore: 1)
Anales de Cirugia Vascular     Full-text available via subscription   (Followers: 1)
Anales de Pediatría     Full-text available via subscription   (Followers: 3, SJR: 0.277, CiteScore: 0)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription  
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 5, SJR: 4.849, CiteScore: 10)
Analytica Chimica Acta     Hybrid Journal   (Followers: 44, SJR: 1.512, CiteScore: 5)
Analytica Chimica Acta : X     Open Access  
Analytical Biochemistry     Hybrid Journal   (Followers: 202, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 12, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 14)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 2)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 24, SJR: 0.683, CiteScore: 2)
Angiología     Full-text available via subscription   (SJR: 0.121, CiteScore: 0)
Angiologia e Cirurgia Vascular     Open Access   (Followers: 1, SJR: 0.111, CiteScore: 0)
Animal Behaviour     Hybrid Journal   (Followers: 208, SJR: 1.58, CiteScore: 3)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6, SJR: 0.937, CiteScore: 2)
Animal Reproduction Science     Hybrid Journal   (Followers: 7, SJR: 0.704, CiteScore: 2)

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Similar Journals
Journal Cover
American Journal of Human Genetics
Journal Prestige (SJR): 7.45
Citation Impact (citeScore): 8
Number of Followers: 34  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0002-9297 - ISSN (Online) 1537-6605
Published by Elsevier Homepage  [3184 journals]
  • TIGAR: An Improved Bayesian Tool for Transcriptomic Data Imputation
           Enhances Gene Mapping of Complex Traits
    • Abstract: Publication date: Available online 20 June 2019Source: The American Journal of Human GeneticsAuthor(s): Sini Nagpal, Xiaoran Meng, Michael P. Epstein, Lam C. Tsoi, Matthew Patrick, Greg Gibson, Philip L. De Jager, David A. Bennett, Aliza P. Wingo, Thomas S. Wingo, Jingjing YangThe transcriptome-wide association studies (TWASs) that test for association between the study trait and the imputed gene expression levels from cis-acting expression quantitative trait loci (cis-eQTL) genotypes have successfully enhanced the discovery of genetic risk loci for complex traits. By using the gene expression imputation models fitted from reference datasets that have both genetic and transcriptomic data, TWASs facilitate gene-based tests with GWAS data while accounting for the reference transcriptomic data. The existing TWAS tools like PrediXcan and FUSION use parametric imputation models that have limitations for modeling the complex genetic architecture of transcriptomic data. Therefore, to improve on this, we employ a nonparametric Bayesian method that was originally proposed for genetic prediction of complex traits, which assumes a data-driven nonparametric prior for cis-eQTL effect sizes. The nonparametric Bayesian method is flexible and general because it includes both of the parametric imputation models used by PrediXcan and FUSION as special cases. Our simulation studies showed that the nonparametric Bayesian model improved both imputation R2 for transcriptomic data and the TWAS power over PrediXcan when ≥1% cis-SNPs co-regulate gene expression and gene expression heritability ≤0.2. In real applications, the nonparametric Bayesian method fitted transcriptomic imputation models for 57.8% more genes over PrediXcan, thus improving the power of follow-up TWASs. We implement both parametric PrediXcan and nonparametric Bayesian methods in a convenient software tool “TIGAR” (Transcriptome-Integrated Genetic Association Resource), which imputes transcriptomic data and performs subsequent TWASs using individual-level or summary-level GWAS data.
  • De Novo Variants in TAOK1 Cause Neurodevelopmental
    • Abstract: Publication date: Available online 20 June 2019Source: The American Journal of Human GeneticsAuthor(s): Marija Dulovic-Mahlow, Joanne Trinh, Krishna Kumar Kandaswamy, Geir Julius Braathen, Nataliya Di Donato, Elisa Rahikkala, Skadi Beblo, Martin Werber, Victor Krajka, Øyvind L. Busk, Hauke Baumann, Nouriya Abbas Al-Sannaa, Frauke Hinrichs, Rabea Affan, Nir Navot, Mohammed A. Al Balwi, Gabriela Oprea, Øystein L. Holla, Maximilian E.R. Weiss, Rami A. JamraDe novo variants represent a significant cause of neurodevelopmental delay and intellectual disability. A genetic basis can be identified in only half of individuals who have neurodevelopmental disorders (NDDs); this indicates that additional causes need to be elucidated. We compared the frequency of de novo variants in patient-parent trios with (n = 2,030) versus without (n = 2,755) NDDs. We identified de novo variants in TAOK1 (thousand and one [TAO] amino acid kinase 1), which encodes the serine/threonine-protein kinase TAO1, in three individuals with NDDs but not in persons who did not have NDDs. Through further screening and the use of GeneMatcher, five additional individuals with NDDs were found to have de novo variants. All eight variants were absent from gnomAD (Genome Aggregation Database). The variant carriers shared a non-specific phenotype of developmental delay, and six individuals had additional muscular hypotonia. We established a fibroblast line of one mutation carrier, and we demonstrated that reduced mRNA levels of TAOK1 could be increased upon cycloheximide treatment. These results indicate nonsense-mediated mRNA decay. Further, there was neither detectable phosphorylated TAO1 kinase nor phosphorylated tau in these cells, and mitochondrial morphology was altered. Knockdown of the ortholog gene Tao1 (Tao, CG14217) in Drosophila resulted in delayed early development. The majority of the Tao1-knockdown flies did not survive beyond the third instar larval stage. When compared to control flies, Tao1 knockdown flies revealed changed morphology of the ventral nerve cord and the neuromuscular junctions as well as a decreased number of endings (boutons). Furthermore, mitochondria in mutant flies showed altered distribution and decreased size in axons of motor neurons. Thus, we provide compelling evidence that de novo variants in TAOK1 cause NDDs.
  • NCALD Antisense Oligonucleotide Therapy in Addition to Nusinersen further
           Ameliorates Spinal Muscular Atrophy in Mice
    • Abstract: Publication date: Available online 20 June 2019Source: The American Journal of Human GeneticsAuthor(s): Laura Torres-Benito, Svenja Schneider, Roman Rombo, Karen K. Ling, Vanessa Grysko, Aaradhita Upadhyay, Natalia L. Kononenko, Frank Rigo, C. Frank Bennett, Brunhilde WirthSpinal muscular atrophy (SMA) is a neuromuscular disease causing the most frequent genetic childhood lethality. Recently, nusinersen, an antisense oligonucleotide (ASO) that corrects SMN2 splicing and thereby increases full-length SMN protein, has been approved by the FDA and EMA for SMA therapy. However, the administration of nusinersen in severe and/or post-symptomatic SMA-affected individuals is insufficient to counteract the disease. Therefore, additional SMN-independent therapies are needed to support the function of motoneurons and neuromuscular junctions. We recently identified asymptomatic SMN1-deleted individuals who were protected against SMA by reduced expression of neurocalcin delta (NCALD). NCALD reduction is proven to be a protective modifier of SMA across species, including worm, zebrafish, and mice. Here, we identified Ncald-ASO3—out of 450 developed Ncald ASOs—as the most efficient and non-toxic ASO for the CNS, by applying a stepwise screening strategy in cortical neurons and adult and neonatal mice. In a randomized-blinded preclinical study, a single subcutaneous low-dose SMN-ASO and a single intracerebroventricular Ncald-ASO3 or control-ASO injection were presymptomatically administered in a severe SMA mouse model. NCALD reduction of>70% persisted for about 1 month. While low-dose SMN-ASO rescues multiorgan impairment, additional NCALD reduction significantly ameliorated SMA pathology including electrophysiological and histological properties of neuromuscular junctions and muscle at P21 and motoric deficits at 3 months. The present study shows the additional benefit of a combinatorial SMN-dependent and SMN-independent ASO-based therapy for SMA. This work illustrates how a modifying gene, identified in some asymptomatic individuals, helps to develop a therapy for all SMA-affected individuals.
  • Bioinformatics-Based Identification of Expanded Repeats: A Non-reference
           Intronic Pentamer Expansion in RFC1 Causes CANVAS
    • Abstract: Publication date: Available online 20 June 2019Source: The American Journal of Human GeneticsAuthor(s): Haloom Rafehi, David J. Szmulewicz, Mark F. Bennett, Nara L.M. Sobreira, Kate Pope, Katherine R. Smith, Greta Gillies, Peter Diakumis, Egor Dolzhenko, Michael A. Eberle, María García Barcina, David P. Breen, Andrew M. Chancellor, Phillip D. Cremer, Martin B. Delatycki, Brent L. Fogel, Anna Hackett, G. Michael Halmagyi, Solange Kapetanovic, Anthony LangGenomic technologies such as next-generation sequencing (NGS) are revolutionizing molecular diagnostics and clinical medicine. However, these approaches have proven inefficient at identifying pathogenic repeat expansions. Here, we apply a collection of bioinformatics tools that can be utilized to identify either known or novel expanded repeat sequences in NGS data. We performed genetic studies of a cohort of 35 individuals from 22 families with a clinical diagnosis of cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS). Analysis of whole-genome sequence (WGS) data with five independent algorithms identified a recessively inherited intronic repeat expansion [(AAGGG)exp] in the gene encoding Replication Factor C1 (RFC1). This motif, not reported in the reference sequence, localized to an Alu element and replaced the reference (AAAAG)11 short tandem repeat. Genetic analyses confirmed the pathogenic expansion in 18 of 22 CANVAS-affected families and identified a core ancestral haplotype, estimated to have arisen in Europe more than twenty-five thousand years ago. WGS of the four RFC1-negative CANVAS-affected families identified plausible variants in three, with genomic re-diagnosis of SCA3, spastic ataxia of the Charlevoix-Saguenay type, and SCA45. This study identified the genetic basis of CANVAS and demonstrated that these improved bioinformatics tools increase the diagnostic utility of WGS to determine the genetic basis of a heterogeneous group of clinically overlapping neurogenetic disorders.
  • The Genomics of Arthrogryposis, a Complex Trait: Candidate Genes and
           Further Evidence for Oligogenic Inheritance
    • Abstract: Publication date: Available online 20 June 2019Source: The American Journal of Human GeneticsAuthor(s): Davut Pehlivan, Yavuz Bayram, Nilay Gunes, Zeynep Coban Akdemir, Anju Shukla, Tatjana Bierhals, Burcu Tabakci, Yavuz Sahin, Alper Gezdirici, Jawid M. Fatih, Elif Yilmaz Gulec, Gozde Yesil, Jaya Punetha, Zeynep Ocak, Christopher M. Grochowski, Ender Karaca, Hatice Mutlu Albayrak, Periyasamy Radhakrishnan, Haktan Bagis Erdem, Ibrahim SahinArthrogryposis is a clinical finding that is present either as a feature of a neuromuscular condition or as part of a systemic disease in over 400 Mendelian conditions. The underlying molecular etiology remains largely unknown because of genetic and phenotypic heterogeneity. We applied exome sequencing (ES) in a cohort of 89 families with the clinical sign of arthrogryposis. Additional molecular techniques including array comparative genomic hybridization (aCGH) and Droplet Digital PCR (ddPCR) were performed on individuals who were found to have pathogenic copy number variants (CNVs) and mosaicism, respectively. A molecular diagnosis was established in 65.2% (58/89) of families. Eleven out of 58 families (19.0%) showed evidence for potential involvement of pathogenic variation at more than one locus, probably driven by absence of heterozygosity (AOH) burden due to identity-by-descent (IBD). RYR3, MYOM2, ERGIC1, SPTBN4, and ABCA7 represent genes, identified in two or more families, for which mutations are probably causative for arthrogryposis. We also provide evidence for the involvement of CNVs in the etiology of arthrogryposis and for the idea that both mono-allelic and bi-allelic variants in the same gene cause either similar or distinct syndromes. We were able to identify the molecular etiology in nine out of 20 families who underwent reanalysis. In summary, our data from family-based ES further delineate the molecular etiology of arthrogryposis, yielded several candidate disease-associated genes, and provide evidence for mutational burden in a biological pathway or network. Our study also highlights the importance of reanalysis of individuals with unsolved diagnoses in conjunction with sequencing extended family members.
  • Genetic and Epigenetic Fine Mapping of Complex Trait Associated Loci in
           the Human Liver
    • Abstract: Publication date: Available online 13 June 2019Source: The American Journal of Human GeneticsAuthor(s): Minal Çalışkan, Elisabetta Manduchi, H. Shanker Rao, Julian A. Segert, Marcia Holsbach Beltrame, Marco Trizzino, YoSon Park, Samuel W. Baker, Alessandra Chesi, Matthew E. Johnson, Kenyaita M. Hodge, Michelle E. Leonard, Baoli Loza, Dong Xin, Andrea M. Berrido, Nicholas J. Hand, Robert C. Bauer, Andrew D. Wells, Kim M. Olthoff, Abraham ShakedDeciphering the impact of genetic variation on gene regulation is fundamental to understanding common, complex human diseases. Although histone modifications are important markers of gene regulatory elements of the genome, any specific histone modification has not been assayed in more than a few individuals in the human liver. As a result, the effects of genetic variation on histone modification states in the liver are poorly understood. Here, we generate the most comprehensive genome-wide dataset of two epigenetic marks, H3K4me3 and H3K27ac, and annotate thousands of putative regulatory elements in the human liver. We integrate these findings with genome-wide gene expression data collected from the same human liver tissues and high-resolution promoter-focused chromatin interaction maps collected from human liver-derived HepG2 cells. We demonstrate widespread functional consequences of natural genetic variation on putative regulatory element activity and gene expression levels. Leveraging these extensive datasets, we fine-map a total of 74 GWAS loci that have been associated with at least one complex phenotype. Our results reveal a repertoire of genes and regulatory mechanisms governing complex disease development and further the basic understanding of genetic and epigenetic regulation of gene expression in the human liver tissue.
  • Systematic Functional Interrogation of Genes in GWAS Loci Identified ATF1
           as a Key Driver in Colorectal Cancer Modulated by a Promoter-Enhancer
    • Abstract: Publication date: Available online 13 June 2019Source: The American Journal of Human GeneticsAuthor(s): Jianbo Tian, Jiang Chang, Jing Gong, Jiao Lou, Mingpeng Fu, Jiaoyuan Li, Juntao Ke, Ying Zhu, Yajie Gong, Yang Yang, Danyi Zou, Xiating Peng, Nan Yang, Shufang Mei, Xiaoyang Wang, Rong Zhong, Kailin Cai, Xiaoping MiaoGenome-wide association studies (GWASs) have identified approximately 100 colorectal cancer (CRC) risk loci. However, the causal genes in these loci have not been systematically interrogated. We conducted a high-throughput RNA-interference functional screen to identify the genes essential for proliferation in the CRC risk loci of Asian populations. We found that ATF1, located in the 12q13.12 region, functions as an oncogene that facilitates cell proliferation; ATF1 has the most significant effect of the identified genes and promotes CRC xenograft growth by affecting cell apoptosis. Next, by integrating a fine-mapping analysis, a two-stage affected-control study consisting of 6,213 affected individuals and 10,388 controls, and multipronged experiments, we elucidated that two risk variants, dbSNP: rs61926301 and dbSNP: rs7959129, that located in the ATF1 promoter and first intron, respectively, facilitate a promoter-enhancer interaction, mediated by the synergy of SP1 and GATA3, to upregulate ATF1 expression, thus synergistically predisposing to CRC risk (OR = 1.77, 95% CI = 1.42–2.21, p = 3.16 × 10−7; Pmultiplicative-interaction = 1.20 × 10−22; Padditive-interaction = 6.50 × 10−3). Finally, we performed RNA-seq and ChIP-seq assays in CRC cells treated with ATF1 overexpression in order to dissect the target programs of ATF1. Results showed that ATF1 activates a subset of genes, including BRAF, NRAS, MYC, BIRC2, DAAM1, MAML2, STAT1, ID1, and NKD2, related to apoptosis, Wnt, TGF-β, and MAPK pathways, and these effects could cooperatively increase the risk of CRC. These findings reveal the clinical potential of ATF1 in CRC development and illuminate a promoter-enhancer interaction module between the ATF1 regulatory elements dbSNP: rs61926301 and dbSNP: rs7959129, and they bring us closer to understanding the molecular drivers of cancer.
  • RINT1 Bi-allelic Variations Cause Infantile-Onset Recurrent Acute Liver
           Failure and Skeletal Abnormalities
    • Abstract: Publication date: Available online 13 June 2019Source: The American Journal of Human GeneticsAuthor(s): Margot A. Cousin, Erin Conboy, Jian-She Wang, Dominic Lenz, Tanya L. Schwab, Monique Williams, Roshini S. Abraham, Sarah Barnett, Mounif El-Youssef, Rondell P. Graham, Luz Helena Gutierrez Sanchez, Linda Hasadsri, Georg F. Hoffmann, Nathan C. Hull, Robert Kopajtich, Reka Kovacs-Nagy, Jia-qi Li, Daniela Marx-Berger, Valérie McLin, Mark A. McNivenPediatric acute liver failure (ALF) is life threatening with genetic, immunologic, and environmental etiologies. Approximately half of all cases remain unexplained. Recurrent ALF (RALF) in infants describes repeated episodes of severe liver injury with recovery of hepatic function between crises. We describe bi-allelic RINT1 alterations as the cause of a multisystem disorder including RALF and skeletal abnormalities. Three unrelated individuals with RALF onset ≤3 years of age have splice alterations at the same position (c.1333+1G>A or G>T) in trans with a missense (p.Ala368Thr or p.Leu370Pro) or in-frame deletion (p.Val618_Lys619del) in RINT1. ALF episodes are concomitant with fever/infection and not all individuals have complete normalization of liver function testing between episodes. Liver biopsies revealed nonspecific liver damage including fibrosis, steatosis, or mild increases in Kupffer cells. Skeletal imaging revealed abnormalities affecting the vertebrae and pelvis. Dermal fibroblasts showed splice-variant mediated skipping of exon 9 leading to an out-of-frame product and nonsense-mediated transcript decay. Fibroblasts also revealed decreased RINT1 protein, abnormal Golgi morphology, and impaired autophagic flux compared to control. RINT1 interacts with NBAS, recently implicated in RALF, and UVRAG, to facilitate Golgi-to-ER retrograde vesicle transport. During nutrient depletion or infection, Golgi-to-ER transport is suppressed and autophagy is promoted through UVRAG regulation by mTOR. Aberrant autophagy has been associated with the development of similar skeletal abnormalities and also with liver disease, suggesting that disruption of these RINT1 functions may explain the liver and skeletal findings. Clarifying the pathomechanism underlying this gene-disease relationship may inform therapeutic opportunities.
  • Genes for Good: Engaging the Public in Genetics Research via Social Media
    • Abstract: Publication date: Available online 13 June 2019Source: The American Journal of Human GeneticsAuthor(s): Katharine Brieger, Gregory J.M. Zajac, Anita Pandit, Johanna R. Foerster, Kevin W. Li, Aubrey C. Annis, Ellen M. Schmidt, Chris P. Clark, Karly McMorrow, Wei Zhou, Jingjing Yang, Alan M. Kwong, Andrew P. Boughton, Jinxi Wu, Chris Scheller, Tanvi Parikh, Alejandro de la Vega, David M. Brazel, Maia Frieser, Gianna Rea-SandinThe Genes for Good study uses social media to engage a large, diverse participant pool in genetics research and education. Health history and daily tracking surveys are administered through a Facebook application, and participants who complete a minimum number of surveys are mailed a saliva sample kit (“spit kit”) to collect DNA for genotyping. As of March 2019, we engaged>80,000 individuals, sent spit kits to>32,000 individuals who met minimum participation requirements, and collected>27,000 spit kits. Participants come from all 50 states and include a diversity of ancestral backgrounds. Rates of important chronic health indicators are consistent with those estimated for the general U.S. population using more traditional study designs. However, our sample is younger and contains a greater percentage of females than the general population. As one means of verifying data quality, we have replicated genome-wide association studies (GWASs) for exemplar traits, such as asthma, diabetes, body mass index (BMI), and pigmentation. The flexible framework of the web application makes it relatively simple to add new questionnaires and for other researchers to collaborate. We anticipate that the study sample will continue to grow and that future analyses may further capitalize on the strengths of the longitudinal data in combination with genetic information.
  • Third-Party Genetic Interpretation Tools: A Mixed-Methods Study of
           Consumer Motivation and Behavior
    • Abstract: Publication date: Available online 13 June 2019Source: The American Journal of Human GeneticsAuthor(s): Sarah C. Nelson, Deborah J. Bowen, Stephanie M. FullertonIn an effort to meet ethical obligations and/or participant expectations, researchers may consider offering “raw” or uninterpreted genetic data for result return. It is therefore important to understand the motivations, behaviors, and perspectives of individuals who might choose to access raw data before such return becomes routine. In the direct-to-consumer (DTC) context, where raw data are often made available to customers, the use of third-party interpretation tools has raised concerns about genotype accuracy, data privacy, reliability of interpretation, and consumption of limited health care resources. However, relatively little is known about why individuals access raw data or what they do with the information received from third-party interpretation. Accordingly, we conducted a survey on raw data access and third-party tool usage among 1,137 DTC customers recruited through social media. Most survey respondents (89%) reported downloading their raw data. Among downloaders, 94% used at least one tool, most commonly Promethease (63%) or GEDmatch (84%). More than half (56%) used both health-related and non-health-related tools and differed significantly from those who used only one tool type in terms of demographics, participation in research, DTC tests ordered, and testing motivations. Exploratory interviews were conducted with 10 respondents and illustrated how social networking, initial lack of interesting findings, and general curiosity contributed to use of multiple tool types. These results suggest that even when initially motivated by ancestry and genealogy, consumers frequently also pursue health information in a largely unregulated and expanding suite of third-party tools, raising both challenges and opportunities for the professional genetics community.
  • Truncating Mutations in UBAP1 Cause Hereditary Spastic Paraplegia
    • Abstract: Publication date: 6 June 2019Source: The American Journal of Human Genetics, Volume 104, Issue 6Author(s): Mohammad Ali Farazi Fard, Adriana P. Rebelo, Elena Buglo, Hamid Nemati, Hassan Dastsooz, Ina Gehweiler, Selina Reich, Jennifer Reichbauer, Beatriz Quintáns, Andrés Ordóñez-Ugalde, Andrea Cortese, Steve Courel, Lisa Abreu, Eric Powell, Matt C. Danzi, Nicole B. Martuscelli, Dana M. Bis-Brewer, Feifei Tao, Fariba Zarei, Parham Habibzadeh
  • Mutations in DNAH17, Encoding a Sperm-Specific Axonemal Outer Dynein Arm
           Heavy Chain, Cause Isolated Male Infertility Due to Asthenozoospermia
    • Abstract: Publication date: Available online 6 June 2019Source: The American Journal of Human GeneticsAuthor(s): Marjorie Whitfield, Lucie Thomas, Emilie Bequignon, Alain Schmitt, Laurence Stouvenel, Guy Montantin, Sylvie Tissier, Philippe Duquesnoy, Bruno Copin, Sandra Chantot, Florence Dastot, Catherine Faucon, Anne Laure Barbotin, Anne Loyens, Jean-Pierre Siffroi, Jean-François Papon, Estelle Escudier, Serge Amselem, Valérie Mitchell, Aminata TouréMotile cilia and sperm flagella share an evolutionarily conserved axonemal structure. Their structural and/or functional defects are associated with primary ciliary dyskinesia (PCD), a genetic disease characterized by chronic respiratory-tract infections and in which most males are infertile due to asthenozoospermia. Among the well-characterized axonemal protein complexes, the outer dynein arms (ODAs), through ATPase activity of their heavy chains (HCs), play a major role for cilia and flagella beating. However, the contribution of the different HCs (γ−type: DNAH5 and DNAH8 and β−type: DNAH9, DNAH11, and DNAH17) in ODAs from both organelles is unknown. By analyzing five male individuals who consulted for isolated infertility and displayed a loss of ODAs in their sperm cells but not in their respiratory cells, we identified bi-allelic mutations in DNAH17. The isolated infertility phenotype prompted us to compare the protein composition of ODAs in the sperm and ciliary axonemes from control individuals. We show that DNAH17 and DNAH8, but not DNAH5, DNAH9, or DNAH11, colocalize with α-tubulin along the sperm axoneme, whereas the reverse picture is observed in respiratory cilia, thus explaining the phenotype restricted to sperm cells. We also demonstrate the loss of function associated with DNAH17 mutations in two unrelated individuals by performing immunoblot and immunofluorescence analyses on sperm cells; these analyses indicated the absence of DNAH17 and DNAH8, whereas DNAH2 and DNALI, two inner dynein arm components, were present. Overall, this study demonstrates that mutations in DNAH17 are responsible for isolated male infertility and provides information regarding ODA composition in human spermatozoa.
  • This Month in The Journal
    • Abstract: Publication date: 6 June 2019Source: The American Journal of Human Genetics, Volume 104, Issue 6Author(s): Sarah Ratzel, Sara B. Cullinan
  • Pathogenic Variants in NUP214 Cause “Plugged” Nuclear Pore Channels
           and Acute Febrile Encephalopathy
    • Abstract: Publication date: Available online 6 June 2019Source: The American Journal of Human GeneticsAuthor(s): Boris Fichtman, Tamar Harel, Nitzan Biran, Fadia Zagairy, Carolyn D. Applegate, Yuval Salzberg, Tal Gilboa, Somaya Salah, Avraham Shaag, Natalia Simanovsky, Houriya Ayoubieh, Nara Sobreira, Giuseppe Punzi, Ciro Leonardo Pierri, Ada Hamosh, Orly Elpeleg, Amnon Harel, Simon EdvardsonWe report biallelic missense and frameshift pathogenic variants in the gene encoding human nucleoporin NUP214 causing acute febrile encephalopathy. Clinical symptoms include neurodevelopmental regression, seizures, myoclonic jerks, progressive microcephaly, and cerebellar atrophy. NUP214 and NUP88 protein levels were reduced in primary skin fibroblasts derived from affected individuals, while the total number and density of nuclear pore complexes remained normal. Nuclear transport assays exhibited defects in the classical protein import and mRNA export pathways in affected cells. Direct surface imaging of fibroblast nuclei by scanning electron microscopy revealed a large increase in the presence of central particles (known as “plugs”) in the nuclear pore channels of affected cells. This observation suggests that large transport cargoes may be delayed in passage through the nuclear pore channel, affecting its selective barrier function. Exposure of fibroblasts from affected individuals to heat shock resulted in a marked delay in their stress response, followed by a surge in apoptotic cell death. This suggests a mechanistic link between decreased cell survival in cell culture and severe fever-induced brain damage in affected individuals. Our study provides evidence by direct imaging at the single nuclear pore level of functional changes linked to a human disease.
  • Expansion of Human-Specific GGC Repeat in Neuronal Intranuclear Inclusion
           Disease-Related Disorders
    • Abstract: Publication date: Available online 6 June 2019Source: The American Journal of Human GeneticsAuthor(s): Yun Tian, Jun-Ling Wang, Wen Huang, Sheng Zeng, Bin Jiao, Zhen Liu, Zhao Chen, Yujing Li, Ying Wang, Hao-Xuan Min, Xue-Jing Wang, Yong You, Ru-Xu Zhang, Xiao-Yu Chen, Fang Yi, Ya-Fang Zhou, Hong-Yu Long, Chao-Jun Zhou, Xuan Hou, Jun-Pu WangNeuronal intranuclear inclusion disease (NIID) is a slowly progressing neurodegenerative disease characterized by eosinophilic intranuclear inclusions in the nervous system and multiple visceral organs. The clinical manifestation of NIID varies widely, and both familial and sporadic cases have been reported. Here we have performed genetic linkage analysis and mapped the disease locus to 1p13.3-q23.1; however, whole-exome sequencing revealed no potential disease-causing mutations. We then performed long-read genome sequencing and identified a large GGC repeat expansion within human-specific NOTCH2NLC. Expanded GGC repeats as the cause of NIID was further confirmed in an additional three NIID-affected families as well as five sporadic NIID-affected case subjects. Moreover, given the clinical heterogeneity of NIID, we examined the size of the GGC repeat among 456 families with a variety of neurological conditions with the known pathogenic genes excluded. Surprisingly, GGC repeat expansion was observed in two Alzheimer disease (AD)-affected families and three parkinsonism-affected families, implicating that the GGC repeat expansions in NOTCH2NLC could also contribute to the pathogenesis of both AD and PD. Therefore, we suggest defining a term NIID-related disorders (NIIDRD), which will include NIID and other related neurodegenerative diseases caused by the expanded GGC repeat within human-specific NOTCH2NLC.
  • Exome-Derived Adiponectin-Associated Variants Implicate Obesity and Lipid
    • Abstract: Publication date: Available online 6 June 2019Source: The American Journal of Human GeneticsAuthor(s): Cassandra N. Spracklen, Tugce Karaderi, Hanieh Yaghootkar, Claudia Schurmann, Rebecca S. Fine, Zoltan Kutalik, Michael H. Preuss, Yingchang Lu, Laura B.L. Wittemans, Linda S. Adair, Matthew Allison, Najaf Amin, Paul L. Auer, Traci M. Bartz, Matthias Blüher, Michael Boehnke, Judith B. Borja, Jette Bork-Jensen, Linda Broer, Daniel I. ChasmanCirculating levels of adiponectin, an adipocyte-secreted protein associated with cardiovascular and metabolic risk, are highly heritable. To gain insights into the biology that regulates adiponectin levels, we performed an exome array meta-analysis of 265,780 genetic variants in 67,739 individuals of European, Hispanic, African American, and East Asian ancestry. We identified 20 loci associated with adiponectin, including 11 that had been reported previously (p < 2 × 10−7). Comparison of exome array variants to regional linkage disequilibrium (LD) patterns and prior genome-wide association study (GWAS) results detected candidate variants (r2> .60) spanning as much as 900 kb. To identify potential genes and mechanisms through which the previously unreported association signals act to affect adiponectin levels, we assessed cross-trait associations, expression quantitative trait loci in subcutaneous adipose, and biological pathways of nearby genes. Eight of the nine loci were also associated (p < 1 × 10−4) with at least one obesity or lipid trait. Candidate genes include PRKAR2A, PTH1R, and HDAC9, which have been suggested to play roles in adipocyte differentiation or bone marrow adipose tissue. Taken together, these findings provide further insights into the processes that influence circulating adiponectin levels.
  • Fast and Accurate Shared Segment Detection and Relatedness Estimation in
           Un-phased Genetic Data via TRUFFLE
    • Abstract: Publication date: Available online 6 June 2019Source: The American Journal of Human GeneticsAuthor(s): Apostolos Dimitromanolakis, Andrew D. Paterson, Lei SunRelationship estimation and segment detection between individuals is an important aspect of disease gene mapping. Existing methods are either tailored for computational efficiency or require phasing to improve accuracy. We developed TRUFFLE, a method that integrates computational techniques and statistical principles for the identification and visualization of identity-by-descent (IBD) segments using un-phased data. By skipping the haplotype phasing step and, instead, relying on a simpler region-based approach, our method is computationally efficient while maintaining inferential accuracy. In addition, an error model corrects for segment break-ups that occur as a consequence of genotyping errors. TRUFFLE can estimate relatedness for 3.1 million pairs from the 1000 Genomes Project data in a few minutes on a typical laptop computer. Consistent with expectation, we identified only three second cousin or closer pairs across different populations, while commonly used methods identified a large number of such pairs. Similarly, within populations, we identified many fewer related pairs. Compared to methods relying on phased data, TRUFFLE has comparable accuracy but is drastically faster and has fewer broken segments. We also identified specific local genomic regions that are commonly shared within populations, suggesting selection. When applied to pedigree data, we observed 99.6% accuracy in detecting 1st to 5th degree relationships. As genomic datasets become much larger, TRUFFLE can enable disease gene mapping through implicit shared haplotypes by accurate IBD segment detection.
  • Lysosomal Storage and Albinism Due to Effects of a De Novo CLCN7 Variant
           on Lysosomal Acidification
    • Abstract: Publication date: Available online 30 May 2019Source: The American Journal of Human GeneticsAuthor(s): Elena-Raluca Nicoli, Mary R. Weston, Mary Hackbarth, Alissa Becerril, Austin Larson, Wadih M. Zein, Peter R. Baker, John Douglas Burke, Heidi Dorward, Mariska Davids, Yan Huang, David R. Adams, Patricia M. Zerfas, Dong Chen, Thomas C. Markello, Camilo Toro, Tim Wood, Gene Elliott, Mylinh Vu, Maria T. AcostaOptimal lysosome function requires maintenance of an acidic pH maintained by proton pumps in combination with a counterion transporter such as the Cl−/H+ exchanger, CLCN7 (ClC-7), encoded by CLCN7. The role of ClC-7 in maintaining lysosomal pH has been controversial. In this paper, we performed clinical and genetic evaluations of two children of different ethnicities. Both children had delayed myelination and development, organomegaly, and hypopigmentation, but neither had osteopetrosis. Whole-exome and -genome sequencing revealed a de novo c.2144A>G variant in CLCN7 in both affected children. This p.Tyr715Cys variant, located in the C-terminal domain of ClC-7, resulted in increased outward currents when it was heterologously expressed in Xenopus oocytes. Fibroblasts from probands displayed a lysosomal pH approximately 0.2 units lower than that of control cells, and treatment with chloroquine normalized the pH. Primary fibroblasts from both probands also exhibited markedly enlarged intracellular vacuoles; this finding was recapitulated by the overexpression of human p.Tyr715Cys CLCN7 in control fibroblasts, reflecting the dominant, gain-of-function nature of the variant. A mouse harboring the knock-in Clcn7 variant exhibited hypopigmentation, hepatomegaly resulting from abnormal storage, and enlarged vacuoles in cultured fibroblasts. Our results show that p.Tyr715Cys is a gain-of-function CLCN7 variant associated with developmental delay, organomegaly, and hypopigmentation resulting from lysosomal hyperacidity, abnormal storage, and enlarged intracellular vacuoles. Our data supports the hypothesis that the ClC-7 antiporter plays a critical role in maintaining lysosomal pH.
  • Geographic Variation and Bias in the Polygenic Scores of Complex Diseases
           and Traits in Finland
    • Abstract: Publication date: Available online 30 May 2019Source: The American Journal of Human GeneticsAuthor(s): Sini Kerminen, Alicia R. Martin, Jukka Koskela, Sanni E. Ruotsalainen, Aki S. Havulinna, Ida Surakka, Aarno Palotie, Markus Perola, Veikko Salomaa, Mark J. Daly, Samuli Ripatti, Matti PirinenPolygenic scores (PSs) are becoming a useful tool to identify individuals with high genetic risk for complex diseases, and several projects are currently testing their utility for translational applications. It is also tempting to use PSs to assess whether genetic variation can explain a part of the geographic distribution of a phenotype. However, it is not well known how the population genetic properties of the training and target samples affect the geographic distribution of PSs. Here, we evaluate geographic differences, and related biases, of PSs in Finland in a geographically well-defined sample of 2,376 individuals from the National FINRISK study. First, we detect geographic differences in PSs for coronary artery disease (CAD), rheumatoid arthritis, schizophrenia, waist-hip ratio (WHR), body-mass index (BMI), and height, but not for Crohn disease or ulcerative colitis. Second, we use height as a model trait to thoroughly assess the possible population genetic biases in PSs and apply similar approaches to the other phenotypes. Most importantly, we detect suspiciously large accumulations of geographic differences for CAD, WHR, BMI, and height, suggesting bias arising from the population’s genetic structure rather than from a direct genotype-phenotype association. This work demonstrates how sensitive the geographic patterns of current PSs are for small biases even within relatively homogeneous populations and provides simple tools to identify such biases. A thorough understanding of the effects of population genetic structure on PSs is essential for translational applications of PSs.
  • Gain-of-Function Mutations in KCNN3 Encoding the Small-Conductance
           Ca2+-Activated K+ Channel SK3 Cause Zimmermann-Laband Syndrome
    • Abstract: Publication date: Available online 30 May 2019Source: The American Journal of Human GeneticsAuthor(s): Christiane K. Bauer, Pauline E. Schneeberger, Fanny Kortüm, Janine Altmüller, Fernando Santos-Simarro, Laura Baker, Jennifer Keller-Ramey, Susan M. White, Philippe M. Campeau, Karen W. Gripp, Kerstin KutscheZimmermann-Laband syndrome (ZLS) is characterized by coarse facial features with gingival enlargement, intellectual disability (ID), hypertrichosis, and hypoplasia or aplasia of nails and terminal phalanges. De novo missense mutations in KCNH1 and KCNK4, encoding K+ channels, have been identified in subjects with ZLS and ZLS-like phenotype, respectively. We report de novo missense variants in KCNN3 in three individuals with typical clinical features of ZLS. KCNN3 (SK3/KCa2.3) constitutes one of three members of the small-conductance Ca2+-activated K+ (SK) channels that are part of a multiprotein complex consisting of the pore-forming channel subunits, the constitutively bound Ca2+ sensor calmodulin, protein kinase CK2, and protein phosphatase 2A. CK2 modulates Ca2+ sensitivity of the channels by phosphorylating SK-bound calmodulin. Patch-clamp whole-cell recordings of KCNN3 channel-expressing CHO cells demonstrated that disease-associated mutations result in gain of function of the mutant channels, characterized by increased Ca2+ sensitivity leading to faster and more complete activation of KCNN3 mutant channels. Pretreatment of cells with the CK2 inhibitor 4,5,6,7-tetrabromobenzotriazole revealed basal inhibition of wild-type and mutant KCNN3 channels by CK2. Analogous experiments with the KCNN3 p.Val450Leu mutant previously identified in a family with portal hypertension indicated basal constitutive channel activity and thus a different gain-of-function mechanism compared to the ZLS-associated mutant channels. With the report on de novo KCNK4 mutations in subjects with facial dysmorphism, hypertrichosis, epilepsy, ID, and gingival overgrowth, we propose to combine the phenotypes caused by mutations in KCNH1, KCNK4, and KCNN3 in a group of neurological potassium channelopathies caused by an increase in K+ conductance.
  • Estimating the Effectiveness of DPYD Genotyping in Italian Individuals
           Suffering from Cancer Based on the Cost of Chemotherapy-Induced Toxicity
    • Abstract: Publication date: Available online 30 May 2019Source: The American Journal of Human GeneticsAuthor(s): Vasileios Fragoulakis, Rossana Roncato, Chiara Dalle Fratte, Fabrizio Ecca, Marina Bartsakoulia, Federico Innocenti, Giuseppe Toffoli, Erika Cecchin, George P. Patrinos, Christina MitropoulouFluoropyrimidines (FLs) have been widely used for more than 60 years against a range of solid tumors and still remains the cornerstone for the treatment of colorectal, gastric, and breast cancer. Here, we performed an economic analysis to estimate the cost of DPYD-guided toxicity management and the clinical benefit expressed as quality adjusted life years (QALYs) in a large group of 571 individuals of Italian origin suffering from cancer and treated with a fluoropyrimidines-based chemotherapy. Individuals suffering from cancer with a histologically confirmed diagnosis of cancer, who received a fluoropyrimidines-based treatment, were retrospectively genotyped in the DPYD gene. Effectiveness was measured as survival of individuals from chemotherapy, while study data on safety and efficacy as well as on resource utilization associated with each adverse drug reaction were used to measure costs to treat these adverse drug reactions. A generalized linear regression model was used to estimate cost differences for both study groups. DPYD extensive metabolizers (528 individuals) had greater effectiveness and lesser cost, representing a cost-saving option over DPYD intermediate and poor metabolizers (43 individuals) with mean QALYs of 4.18 (95%CI: 3.16–5.55) versus 3.02 (95%CI: 1.94–4.25), respectively. Our economic analysis showed that there are some indications for differences in survival between the two groups (p> 0.05), while the cost of DPYD extensive metabolizers was significantly lower (p < 0.01) compared with those belonging to the group of intermediate/poor metabolizers. These findings suggest that DPYD-guided fluoropyrimidines treatment represent a cost-saving choice for individuals suffering from cancer in the Italian healthcare setting.
  • Impact and Evolutionary Determinants of Neanderthal Introgression on
           Transcriptional and Post-Transcriptional Regulation
    • Abstract: Publication date: Available online 30 May 2019Source: The American Journal of Human GeneticsAuthor(s): Martin Silvert, Lluis Quintana-Murci, Maxime RotivalArchaic admixture is increasingly recognized as an important source of diversity in modern humans, and Neanderthal haplotypes cover 1%–3% of the genome of present-day Eurasians. Recent work has shown that archaic introgression has contributed to human phenotypic diversity, mostly through the regulation of gene expression. Yet the mechanisms through which archaic variants alter gene expression and the forces driving the introgression landscape at regulatory regions remain elusive. Here, we explored the impact of archaic introgression on transcriptional and post-transcriptional regulation. We focused on promoters and enhancers across 127 different tissues as well as on microRNA (miRNA)-mediated regulation. Although miRNAs themselves harbor few archaic variants, we found that some of these variants may have a strong impact on miRNA-mediated gene regulation. Enhancers were by far the regulatory elements most affected by archaic introgression: up to one-third of the tissues we tested presented significant enrichments. Specifically, we found strong enrichments of archaic variants in adipose-related tissues and primary T cells, even after accounting for various genomic and evolutionary confounders such as recombination rate and background selection. Interestingly, we identified signatures of adaptive introgression at enhancers of some key regulators of adipogenesis, raising the interesting hypothesis of a possible adaptation of early Eurasians to colder climates. Collectively, this study sheds new light on the mechanisms through which archaic admixture has impacted gene regulation in Eurasians and, more generally, increases our understanding of the contribution of Neanderthals to the regulation of acquired immunity and adipose homeostasis in modern humans.
  • Cell-Type Heterogeneity in Adipose Tissue Is Associated with Complex
           Traits and Reveals Disease-Relevant Cell-Specific eQTLs
    • Abstract: Publication date: Available online 23 May 2019Source: The American Journal of Human GeneticsAuthor(s): Craig A. Glastonbury, Alexessander Couto Alves, Julia S. El-Sayed Moustafa, Kerrin S. SmallAdipose tissue is an important endocrine organ with a role in many cardiometabolic diseases. It is comprised of a heterogeneous collection of cell types that can differentially impact disease phenotypes. Cellular heterogeneity can also confound -omic analyses but is rarely taken into account in analysis of solid-tissue transcriptomes. Here, we investigate cell-type heterogeneity in two population-level subcutaneous adipose-tissue RNA-seq datasets (TwinsUK, n = 766 and the Genotype-Tissue Expression project [GTEx], n = 326) by estimating the relative proportions of four distinct cell types (adipocytes, macrophages, CD4+ T cells, and micro-vascular endothelial cells). We find significant cellular heterogeneity within and between the TwinsUK and GTEx adipose datasets. We find that adipose cell-type composition is heritable and confirm the positive association between adipose-resident macrophage proportion and obesity (high BMI), but we find a stronger BMI-independent association with dual-energy X-ray absorptiometry (DXA) derived body-fat distribution traits. We benchmark the impact of adipose-tissue cell composition on a range of standard analyses, including phenotype-gene expression association, co-expression networks, and cis-eQTL discovery. Our results indicate that it is critical to account for cell-type composition when combining adipose transcriptome datasets in co-expression analysis and in differential expression analysis with obesity-related traits. We applied gene expression by cell-type proportion interaction models (G × Cell) to identify 26 cell-type-specific expression quantitative trait loci (eQTLs) in 20 genes, including four autoimmune disease genome-wide association study (GWAS) loci. These results identify cell-specific eQTLs and demonstrate the potential of in silico deconvolution of bulk tissue to identify cell-type-restricted regulatory variants.
  • Germline-Activating RRAS2 Mutations Cause Noonan Syndrome
    • Abstract: Publication date: Available online 23 May 2019Source: The American Journal of Human GeneticsAuthor(s): Tetsuya Niihori, Koki Nagai, Atsushi Fujita, Hirofumi Ohashi, Nobuhiko Okamoto, Satoshi Okada, Atsuko Harada, Hirotaka Kihara, Thomas Arbogast, Ryo Funayama, Matsuyuki Shirota, Keiko Nakayama, Taiki Abe, Shin-ichi Inoue, I-Chun Tsai, Naomichi Matsumoto, Erica E. Davis, Nicholas Katsanis, Yoko AokiNoonan syndrome (NS) is characterized by distinctive craniofacial appearance, short stature, and congenital heart disease. Approximately 80% of individuals with NS harbor mutations in genes whose products are involved in the RAS/mitogen-activating protein kinase (MAPK) pathway. However, the underlying genetic causes in nearly 20% of individuals with NS phenotype remain unexplained. Here, we report four de novo RRAS2 variants in three individuals with NS. RRAS2 is a member of the RAS subfamily and is ubiquitously expressed. Three variants, c.70_78dup (p.Gly24_Gly26dup), c.216A>T (p.Gln72His), and c.215A>T (p.Gln72Leu), have been found in cancers; our functional analyses showed that these three changes induced elevated association of RAF1 and that they activated ERK1/2 and ELK1. Notably, prominent activation of ERK1/2 and ELK1 by p.Gln72Leu associates with the severe phenotype of the individual harboring this change. To examine variant pathogenicity in vivo, we generated zebrafish models. Larvae overexpressing c.70_78dup (p.Gly24_Gly26dup) or c.216A>T (p.Gln72His) variants, but not wild-type RRAS2 RNAs, showed craniofacial defects and macrocephaly. The same dose injection of mRNA encoding c.215A>T (p.Gln72Leu) caused severe developmental impairments and low dose overexpression of this variant induced craniofacial defects. In contrast, the RRAS2 c.224T>G (p.Phe75Cys) change, located on the same allele with p.Gln72His in an individual with NS, resulted in no aberrant in vitro or in vivo phenotypes by itself. Together, our findings suggest that activating RRAS2 mutations can cause NS and expand the involvement of RRAS2 proto-oncogene to rare germline disorders.
  • Activating Mutations of RRAS2 Are a Rare Cause of Noonan Syndrome
    • Abstract: Publication date: Available online 23 May 2019Source: The American Journal of Human GeneticsAuthor(s): Yline Capri, Elisabetta Flex, Oliver H.F. Krumbach, Giovanna Carpentieri, Serena Cecchetti, Christina Lißewski, Soheila Rezaei Adariani, Denny Schanze, Julia Brinkmann, Juliette Piard, Francesca Pantaleoni, Francesca R. Lepri, Elaine Suk-Ying Goh, Karen Chong, Elliot Stieglitz, Julia Meyer, Alma Kuechler, Nuria C. Bramswig, Stephanie Sacharow, Marion StrulluAberrant signaling through pathways controlling cell response to extracellular stimuli constitutes a central theme in disorders affecting development. Signaling through RAS and the MAPK cascade controls a variety of cell decisions in response to cytokines, hormones, and growth factors, and its upregulation causes Noonan syndrome (NS), a developmental disorder whose major features include a distinctive facies, a wide spectrum of cardiac defects, short stature, variable cognitive impairment, and predisposition to malignancies. NS is genetically heterogeneous, and mutations in more than ten genes have been reported to underlie this disorder. Despite the large number of genes implicated, about 10%–20% of affected individuals with a clinical diagnosis of NS do not have mutations in known RASopathy-associated genes, indicating that additional unidentified genes contribute to the disease, when mutated. By using a mixed strategy of functional candidacy and exome sequencing, we identify RRAS2 as a gene implicated in NS in six unrelated subjects/families. We show that the NS-causing RRAS2 variants affect highly conserved residues localized around the nucleotide binding pocket of the GTPase and are predicted to variably affect diverse aspects of RRAS2 biochemical behavior, including nucleotide binding, GTP hydrolysis, and interaction with effectors. Additionally, all pathogenic variants increase activation of the MAPK cascade and variably impact cell morphology and cytoskeletal rearrangement. Finally, we provide a characterization of the clinical phenotype associated with RRAS2 mutations.
  • Lessons Learned from Large-Scale, First-Tier Clinical Exome Sequencing in
           a Highly Consanguineous Population
    • Abstract: Publication date: Available online 23 May 2019Source: The American Journal of Human GeneticsAuthor(s): Dorota Monies, Mohammed Abouelhoda, Mirna Assoum, Nabil Moghrabi, Rafiullah Rafiullah, Naif Almontashiri, Mohammed Alowain, Hamad Alzaidan, Moeen Alsayed, Shazia Subhani, Edward Cupler, Maha Faden, Amal Alhashem, Alya Qari, Aziza Chedrawi, Hisham Aldhalaan, Wesam Kurdi, Sameena Khan, Zuhair Rahbeeni, Maha AlotaibiWe report the results of clinical exome sequencing (CES) on>2,200 previously unpublished Saudi families as a first-tier test. The predominance of autosomal-recessive causes allowed us to make several key observations. We highlight 155 genes that we propose to be recessive, disease-related candidates. We report additional mutational events in 64 previously reported candidates (40 recessive), and these events support their candidacy. We report recessive forms of genes that were previously associated only with dominant disorders and that have phenotypes ranging from consistent with to conspicuously distinct from the known dominant phenotypes. We also report homozygous loss-of-function events that can inform the genetics of complex diseases. We were also able to deduce the likely causal variant in most couples who presented after the loss of one or more children, but we lack samples from those children. Although a similar pattern of mostly recessive causes was observed in the prenatal setting, the higher proportion of loss-of-function events in these cases was notable. The allelic series presented by the wealth of recessive variants greatly expanded the phenotypic expression of the respective genes. We also make important observations about dominant disorders; these observations include the pattern of de novo variants, the identification of 74 candidate dominant, disease-related genes, and the potential confirmation of 21 previously reported candidates. Finally, we describe the influence of a predominantly autosomal-recessive landscape on the clinical utility of rapid sequencing (Flash Exome). Our cohort’s genotypic and phenotypic data represent a unique resource that can contribute to improved variant interpretation through data sharing.
  • On Using Local Ancestry to Characterize the Genetic Architecture of Human
           Traits: Genetic Regulation of Gene Expression in Multiethnic or Admixed
    • Abstract: Publication date: Available online 16 May 2019Source: The American Journal of Human GeneticsAuthor(s): Yizhen Zhong, Minoli A. Perera, Eric R. GamazonUnderstanding the nature of the genetic regulation of gene expression promises to advance our understanding of the genetic basis of disease. However, the methodological impact of the use of local ancestry on high-dimensional omics analyses, including, most prominently, expression quantitative trait loci (eQTL) mapping and trait heritability estimation, in admixed populations remains critically underexplored. Here, we develop a statistical framework that characterizes the relationships among the determinants of the genetic architecture of an important class of molecular traits. We provide a computationally efficient approach to local ancestry analysis in eQTL mapping while increasing control of type I and type II error over traditional approaches. Applying our method to National Institute of General Medical Sciences (NIGMS) and Genotype-Tissue Expression (GTEx) datasets, we show that the use of local ancestry can improve eQTL mapping in admixed and multiethnic populations, respectively. We estimate the trait variance explained by ancestry by using local admixture relatedness between individuals. By using simulations of diverse genetic architectures and degrees of confounding, we show improved accuracy in estimating heritability when accounting for local ancestry similarity. Furthermore, we characterize the sparse versus polygenic components of gene expression in admixed individuals. Our study has important methodological implications for genetic analysis of omics traits across a range of genomic contexts, from a single variant to a prioritized region to the entire genome. Our findings highlight the importance of using local ancestry to better characterize the heritability of complex traits and to more accurately map genetic associations.
  • Length of Uninterrupted CAG, Independent of Polyglutamine Size, Results in
           Increased Somatic Instability, Hastening Onset of Huntington Disease
    • Abstract: Publication date: Available online 16 May 2019Source: The American Journal of Human GeneticsAuthor(s): Galen E.B. Wright, Jennifer A. Collins, Chris Kay, Cassandra McDonald, Egor Dolzhenko, Qingwen Xia, Kristina Bečanović, Britt I. Drögemöller, Alicia Semaka, Charlotte M. Nguyen, Brett Trost, Fiona Richards, Emilia K. Bijlsma, Ferdinando Squitieri, Colin J.D. Ross, Stephen W. Scherer, Michael A. Eberle, Ryan K.C. Yuen, Michael R. HaydenHuntington disease (HD) is caused by a CAG repeat expansion in the huntingtin (HTT) gene. Although the length of this repeat is inversely correlated with age of onset (AOO), it does not fully explain the variability in AOO. We assessed the sequence downstream of the CAG repeat in HTT [reference: (CAG)n-CAA-CAG], since variants within this region have been previously described, but no study of AOO has been performed. These analyses identified a variant that results in complete loss of interrupting (LOI) adenine nucleotides in this region [(CAG)n-CAG-CAG]. Analysis of multiple HD pedigrees showed that this LOI variant is associated with dramatically earlier AOO (average of 25 years) despite the same polyglutamine length as in individuals with the interrupting penultimate CAA codon. This LOI allele is particularly frequent in persons with reduced penetrance alleles who manifest with HD and increases the likelihood of presenting clinically with HD with a CAG of 36–39 repeats. Further, we show that the LOI variant is associated with increased somatic repeat instability, highlighting this as a significant driver of this effect. These findings indicate that the number of uninterrupted CAG repeats, which is lengthened by the LOI, is the most significant contributor to AOO of HD and is more significant than polyglutamine length, which is not altered in these individuals. In addition, we identified another variant in this region, where the CAA-CAG sequence is duplicated, which was associated with later AOO. Identification of these cis-acting modifiers have potentially important implications for genetic counselling in HD-affected families.
  • A Recurrent Missense Variant in AP2M1 Impairs Clathrin-Mediated
           Endocytosis and Causes Developmental and Epileptic Encephalopathy
    • Abstract: Publication date: Available online 16 May 2019Source: The American Journal of Human GeneticsAuthor(s): Ingo Helbig, Tania Lopez-Hernandez, Oded Shor, Peter Galer, Shiva Ganesan, Manuela Pendziwiat, Annika Rademacher, Colin A. Ellis, Nadja Hümpfer, Niklas Schwarz, Simone Seiffert, Joseph Peeden, Joseph Shen, Katalin Štěrbová, Trine Bjørg Hammer, Rikke S. Møller, Deepali N. Shinde, Sha Tang, Lacey Smith, Annapurna PoduriThe developmental and epileptic encephalopathies (DEEs) are heterogeneous disorders with a strong genetic contribution, but the underlying genetic etiology remains unknown in a significant proportion of individuals. To explore whether statistical support for genetic etiologies can be generated on the basis of phenotypic features, we analyzed whole-exome sequencing data and phenotypic similarities by using Human Phenotype Ontology (HPO) in 314 individuals with DEEs. We identified a de novo c.508C>T (p.Arg170Trp) variant in AP2M1 in two individuals with a phenotypic similarity that was higher than expected by chance (p = 0.003) and a phenotype related to epilepsy with myoclonic-atonic seizures. We subsequently found the same de novo variant in two individuals with neurodevelopmental disorders and generalized epilepsy in a cohort of 2,310 individuals who underwent diagnostic whole-exome sequencing. AP2M1 encodes the μ-subunit of the adaptor protein complex 2 (AP-2), which is involved in clathrin-mediated endocytosis (CME) and synaptic vesicle recycling. Modeling of protein dynamics indicated that the p.Arg170Trp variant impairs the conformational activation and thermodynamic entropy of the AP-2 complex. Functional complementation of both the μ-subunit carrying the p.Arg170Trp variant in human cells and astrocytes derived from AP-2μ conditional knockout mice revealed a significant impairment of CME of transferrin. In contrast, stability, expression levels, membrane recruitment, and localization were not impaired, suggesting a functional alteration of the AP-2 complex as the underlying disease mechanism. We establish a recurrent pathogenic variant in AP2M1 as a cause of DEEs with distinct phenotypic features, and we implicate dysfunction of the early steps of endocytosis as a disease mechanism in epilepsy.
  • The Genomic Medicine Integrative Research Framework: A Conceptual
           Framework for Conducting Genomic Medicine Research
    • Abstract: Publication date: Available online 16 May 2019Source: The American Journal of Human GeneticsAuthor(s): Carol R. Horowitz, Lori A. Orlando, Anne M. Slavotinek, Josh Peterson, Frank Angelo, Barbara Biesecker, Vence L. Bonham, Linda D. Cameron, Stephanie M. Fullerton, Bruce D. Gelb, Katrina A.B. Goddard, Benyam Hailu, Ragan Hart, Lucia A. Hindorff, Gail P. Jarvik, Dave Kaufman, Eimear E. Kenny, Sara J. Knight, Barbara A. Koenig, Bruce R. KorfConceptual frameworks are useful in research because they can highlight priority research domains, inform decisions about interventions, identify outcomes and factors to measure, and display how factors might relate to each other to generate and test hypotheses. Discovery, translational, and implementation research are all critical to the overall mission of genomic medicine and prevention, but they have yet to be organized into a unified conceptual framework. To fill this gap, our diverse team collaborated to develop the Genomic Medicine Integrative Research (GMIR) Framework, a simple but comprehensive tool to aid the genomics community in developing research questions, strategies, and measures and in integrating genomic medicine and prevention into clinical practice. Here we present the GMIR Framework and its development, along with examples of its use for research development, demonstrating how we applied it to select and harmonize measures for use across diverse genomic medicine implementation projects. Researchers can utilize the GMIR Framework for their own research, collaborative investigations, and clinical implementation efforts; clinicians can use it to establish and evaluate programs; and all stakeholders can use it to help allocate resources and make sure that the full complexity of etiology is included in research and program design, development, and evaluation.
  • Bi-allelic Variants in DYNC1I2 Cause Syndromic Microcephaly with
           Intellectual Disability, Cerebral Malformations, and Dysmorphic Facial
    • Abstract: Publication date: Available online 9 May 2019Source: The American Journal of Human GeneticsAuthor(s): Muhammad Ansar, Farid Ullah, Sohail A. Paracha, Darius J. Adams, Abbe Lai, Lynn Pais, Justyna Iwaszkiewicz, Francisca Millan, Muhammad T. Sarwar, Zehra Agha, Sayyed Fahim Shah, Azhar Ali Qaisar, Emilie Falconnet, Vincent Zoete, Emmanuelle Ranza, Periklis Makrythanasis, Federico A. Santoni, Jawad Ahmed, Nicholas Katsanis, Christopher WalshCargo transport along the cytoplasmic microtubular network is essential for neuronal function, and cytoplasmic dynein-1 is an established molecular motor that is critical for neurogenesis and homeostasis. We performed whole-exome sequencing, homozygosity mapping, and chromosomal microarray studies in five individuals from three independent pedigrees and identified likely-pathogenic variants in DYNC1I2 (Dynein Cytoplasmic 1 Intermediate Chain 2), encoding a component of the cytoplasmic dynein 1 complex. In a consanguineous Pakistani family with three affected individuals presenting with microcephaly, severe intellectual disability, simplification of cerebral gyration, corpus callosum hypoplasia, and dysmorphic facial features, we identified a homozygous splice donor site variant (GenBank: NM_001378.2:c.607+1G>A). We report two additional individuals who have similar neurodevelopmental deficits and craniofacial features and harbor deleterious variants; one individual bears a c.740A>G (p.Tyr247Cys) change in trans with a 374 kb deletion encompassing DYNC1I2, and an unrelated individual harbors the compound-heterozygous variants c.868C>T (p.Gln290∗) and c.740A>G (p.Tyr247Cys). Zebrafish larvae subjected to CRISPR-Cas9 gene disruption or transient suppression of dync1i2a displayed significantly altered craniofacial patterning with concomitant reduction in head size. We monitored cell death and cell cycle progression in dync1i2a zebrafish models and observed significantly increased apoptosis, likely due to prolonged mitosis caused by abnormal spindle morphology, and this finding offers initial insights into the cellular basis of microcephaly. Additionally, complementation studies in zebrafish demonstrate that p.Tyr247Cys attenuates gene function, consistent with protein structural analysis. Our genetic and functional data indicate that DYNC1I2 dysfunction probably causes an autosomal-recessive microcephaly syndrome and highlight further the critical roles of the dynein-1 complex in neurodevelopment.
  • Recessive Truncating Mutations in ALKBH8 Cause Intellectual Disability and
           Severe Impairment of Wobble Uridine Modification
    • Abstract: Publication date: Available online 9 May 2019Source: The American Journal of Human GeneticsAuthor(s): Dorota Monies, Cathrine Broberg Vågbø, Mohammad Al-Owain, Suzan Alhomaidi, Fowzan S. AlkurayaThe wobble hypothesis was proposed to explain the presence of fewer tRNAs than possible codons. The wobble nucleoside position in the anticodon stem-loop undergoes a number of modifications that help maintain the efficiency and fidelity of translation. AlkB homolog 8 (ALKBH8) is an atypical member of the highly conserved AlkB family of dioxygenases and is involved in the formation of mcm5s2U, (S)-mchm5U, (R)-mchm5U, mcm5U, and mcm5Um at the anticodon wobble uridines of specific tRNAs. In two multiplex consanguineous families, we identified two homozygous truncating ALKBH8 mutations causing intellectual disability. Analysis of tRNA derived from affected individuals showed the complete absence of these modifications, consistent with the presumptive loss of function of the variants. Our results highlight the sensitivity of the brain to impaired wobble modification and expand the list of intellectual-disability syndromes caused by mutations in genes related to tRNA modification.
  • HNRNPR Variants that Impair Homeobox Gene Expression Drive Developmental
           Disorders in Humans
    • Abstract: Publication date: Available online 9 May 2019Source: The American Journal of Human GeneticsAuthor(s): Floor A. Duijkers, Andrew McDonald, Georges E. Janssens, Marco Lezzerini, Aldo Jongejan, Silvana van Koningsbruggen, Wendela G. Leeuwenburgh-Pronk, Marcin W. Wlodarski, Sébastien Moutton, Frédéric Tran-Mau-Them, Christel Thauvin-Robinet, Laurence Faivre, Kristin G. Monaghan, Thomas Smol, Odile Boute-Benejean, Roger L. Ladda, Susan L. Sell, Ange-Line Bruel, Riekelt H. Houtkooper, Alyson W. MacInnesThe heterogeneous nuclear ribonucleoprotein (HNRNP) genes code for a set of RNA-binding proteins that function primarily in the spliceosome C complex. Pathogenic variants in these genes can drive neurodegeneration, through a mechanism involving excessive stress-granule formation, or developmental defects, through mechanisms that are not known. Here, we report four unrelated individuals who have truncating or missense variants in the same C-terminal region of hnRNPR and who have multisystem developmental defects including abnormalities of the brain and skeleton, dysmorphic facies, brachydactyly, seizures, and hypoplastic external genitalia. We further identified in the literature a fifth individual with a truncating variant. RNA sequencing of primary fibroblasts reveals that these HNRNPR variants drive significant changes in the expression of several homeobox genes, as well as other transcription factors, such as LHX9, TBX1, and multiple HOX genes, that are considered fundamental regulators of embryonic and gonad development. Higher levels of retained intronic HOX sequences and lost splicing events in the HOX cluster are observed in cells carrying HNRNPR variants, suggesting that impaired splicing is at least partially driving HOX deregulation. At basal levels, stress-granule formation appears normal in primary and transfected cells expressing HNRNPR variants. However, these cells reveal profound recovery defects, where stress granules fail to disassemble properly, after exposure to oxidative stress. This study establishes an essential role for HNRNPR in human development and points to a mechanism that may unify other “spliceosomopathies” linked to variants that drive multi-system congenital defects and are found in hnRNPs.
  • Heterozygous Variants in KMT2E Cause a Spectrum of Neurodevelopmental
           Disorders and Epilepsy
    • Abstract: Publication date: Available online 9 May 2019Source: The American Journal of Human GeneticsAuthor(s): Anne H. O’Donnell-Luria, Lynn S. Pais, Víctor Faundes, Jordan C. Wood, Abigail Sveden, Victor Luria, Rami Abou Jamra, Andrea Accogli, Kimberly Amburgey, Britt Marie Anderlid, Silvia Azzarello-Burri, Alice A. Basinger, Claudia Bianchini, Lynne M. Bird, Rebecca Buchert, Wilfrid Carre, Sophia Ceulemans, Perrine Charles, Helen Cox, Lisa CullitonWe delineate a KMT2E-related neurodevelopmental disorder on the basis of 38 individuals in 36 families. This study includes 31 distinct heterozygous variants in KMT2E (28 ascertained from Matchmaker Exchange and three previously reported), and four individuals with chromosome 7q22.2-22.23 microdeletions encompassing KMT2E (one previously reported). Almost all variants occurred de novo, and most were truncating. Most affected individuals with protein-truncating variants presented with mild intellectual disability. One-quarter of individuals met criteria for autism. Additional common features include macrocephaly, hypotonia, functional gastrointestinal abnormalities, and a subtle facial gestalt. Epilepsy was present in about one-fifth of individuals with truncating variants and was responsive to treatment with anti-epileptic medications in almost all. More than 70% of the individuals were male, and expressivity was variable by sex; epilepsy was more common in females and autism more common in males. The four individuals with microdeletions encompassing KMT2E generally presented similarly to those with truncating variants, but the degree of developmental delay was greater. The group of four individuals with missense variants in KMT2E presented with the most severe developmental delays. Epilepsy was present in all individuals with missense variants, often manifesting as treatment-resistant infantile epileptic encephalopathy. Microcephaly was also common in this group. Haploinsufficiency versus gain-of-function or dominant-negative effects specific to these missense variants in KMT2E might explain this divergence in phenotype, but requires independent validation. Disruptive variants in KMT2E are an under-recognized cause of neurodevelopmental abnormalities.
  • Recurrent Germline DLST Mutations in Individuals with Multiple
           Pheochromocytomas and Paragangliomas
    • Abstract: Publication date: 2 May 2019Source: The American Journal of Human Genetics, Volume 104, Issue 5Author(s): Laura Remacha, David Pirman, Christopher E. Mahoney, Javier Coloma, Bruna Calsina, Maria Currás-Freixes, Rocío Letón, Rafael Torres-Pérez, Susan Richter, Guillermo Pita, Belén Herráez, Giovanni Cianchetta, Emiliano Honrado, Lorena Maestre, Miguel Urioste, Javier Aller, Óscar García-Uriarte, María Ángeles Gálvez, Raúl M. Luque, Marcos Lahera
  • Benchmarker: An Unbiased, Association-Data-Driven Strategy to Evaluate
           Gene Prioritization Algorithms
    • Abstract: Publication date: Available online 2 May 2019Source: The American Journal of Human GeneticsAuthor(s): Rebecca S. Fine, Tune H. Pers, Tiffany Amariuta, Soumya Raychaudhuri, Joel N. HirschhornGenome-wide association studies (GWASs) are valuable for understanding human biology, but associated loci typically contain multiple associated variants and genes. Thus, algorithms that prioritize likely causal genes and variants for a given phenotype can provide biological interpretations of association data. However, a critical, currently missing capability is to objectively compare performance of such algorithms. Typical comparisons rely on “gold standard” genes harboring causal coding variants, but such gold standards may be biased and incomplete. To address this issue, we developed Benchmarker, an unbiased, data-driven benchmarking method that compares performance of similarity-based prioritization strategies to each other (and to random chance) by leave-one-chromosome-out cross-validation with stratified linkage disequilibrium (LD) score regression. We first applied Benchmarker to 20 well-powered GWASs and compared gene prioritization based on strategies employing three different data sources, including annotated gene sets and gene expression; genes prioritized based on gene sets had higher per-SNP heritability than those prioritized based on gene expression. Additionally, in a direct comparison of three methods, DEPICT and MAGMA outperformed NetWAS. We also evaluated combinations of methods; our results indicated that combining data sources and algorithms can help prioritize higher-quality genes for follow-up. Benchmarker provides an unbiased approach to evaluate any similarity-based method that provides genome-wide prioritization of genes, variants, or gene sets and can determine the best such method for any particular GWAS. Our method addresses an important unmet need for rigorous tool assessment and can assist in mapping genetic associations to causal function.
  • Rare Variants in BNC2 Are Implicated in Autosomal-Dominant Congenital
           Lower Urinary-Tract Obstruction
    • Abstract: Publication date: 2 May 2019Source: The American Journal of Human Genetics, Volume 104, Issue 5Author(s): Caroline M. Kolvenbach, Gabriel C. Dworschak, Sandra Frese, Anna S. Japp, Peggy Schuster, Nina Wenzlitschke, Öznur Yilmaz, Filipa M. Lopes, Alexey Pryalukhin, Luca Schierbaum, Loes F.M. van der Zanden, Franziska Kause, Ronen Schneider, Katarzyna Taranta-Janusz, Maria Szczepańska, Krzysztof Pawlaczyk, William G. Newman, Glenda M. Beaman, Helen M. Stuart, Raimondo M. CervellioneCongenital lower urinary-tract obstruction (LUTO) is caused by anatomical blockage of the bladder outflow tract or by functional impairment of urinary voiding. About three out of 10,000 pregnancies are affected. Although several monogenic causes of functional obstruction have been defined, it is unknown whether congenital LUTO caused by anatomical blockage has a monogenic cause. Exome sequencing in a family with four affected individuals with anatomical blockage of the urethra identified a rare nonsense variant (c.2557C>T [p.Arg853∗]) in BNC2, encoding basonuclin 2, tracking with LUTO over three generations. Re-sequencing BNC2 in 697 individuals with LUTO revealed three further independent missense variants in three unrelated families. In human and mouse embryogenesis, basonuclin 2 was detected in lower urinary-tract rudiments. In zebrafish embryos, bnc2 was expressed in the pronephric duct and cloaca, analogs of the mammalian lower urinary tract. Experimental knockdown of Bnc2 in zebrafish caused pronephric-outlet obstruction and cloacal dilatation, phenocopying human congenital LUTO. Collectively, these results support the conclusion that variants in BNC2 are strongly implicated in LUTO etiology as a result of anatomical blockage.
  • Genes with High Network Connectivity Are Enriched for Disease Heritability
    • Abstract: Publication date: 2 May 2019Source: The American Journal of Human Genetics, Volume 104, Issue 5Author(s): Samuel S. Kim, Chengzhen Dai, Farhad Hormozdiari, Bryce van de Geijn, Steven Gazal, Yongjin Park, Luke O’Connor, Tiffany Amariuta, Po-Ru Loh, Hilary Finucane, Soumya Raychaudhuri, Alkes L. PriceRecent studies have highlighted the role of gene networks in disease biology. To formally assess this, we constructed a broad set of pathway, network, and pathway+network annotations and applied stratified LD score regression to 42 diseases and complex traits (average N = 323K) to identify enriched annotations. First, we analyzed 18,119 biological pathways. We identified 156 pathway-trait pairs whose disease enrichment was statistically significant (FDR < 5%) after conditioning on all genes and 75 known functional annotations (from the baseline-LD model), a stringent step that greatly reduced the number of pathways detected; most significant pathway-trait pairs were previously unreported. Next, for each of four published gene networks, we constructed probabilistic annotations based on network connectivity. For each gene network, the network connectivity annotation was strongly significantly enriched. Surprisingly, the enrichments were fully explained by excess overlap between network annotations and regulatory annotations from the baseline-LD model, validating the informativeness of the baseline-LD model and emphasizing the importance of accounting for regulatory annotations in gene network analyses. Finally, for each of the 156 enriched pathway-trait pairs, for each of the four gene networks, we constructed pathway+network annotations by annotating genes with high network connectivity to the input pathway. For each gene network, these pathway+network annotations were strongly significantly enriched for the corresponding traits. Once again, the enrichments were largely explained by the baseline-LD model. In conclusion, gene network connectivity is highly informative for disease architectures, but the information in gene networks may be subsumed by regulatory annotations, emphasizing the importance of accounting for known annotations.
  • COL4A1 Mutations Cause Neuromuscular Disease with Tissue-Specific
           Mechanistic Heterogeneity
    • Abstract: Publication date: 2 May 2019Source: The American Journal of Human Genetics, Volume 104, Issue 5Author(s): Cassandre Labelle-Dumais, Vera Schuitema, Genki Hayashi, Kendall Hoff, Wenhui Gong, Dang Q. Dao, Erik M. Ullian, Peter Oishi, Marta Margeta, Douglas B. GouldCollagen type IV alpha 1 and alpha 2 chains form heterotrimers ([α1(IV)]2α2(IV)) that represent a fundamental basement membrane constituent. Dominant COL4A1 and COL4A2 mutations cause a multisystem disorder that is marked by clinical heterogeneity and variable expressivity and that is generally characterized by the presence of cerebrovascular disease with ocular, renal, and muscular involvement. Despite the fact that muscle pathology is reported in up to one-third of individuals with COL4A1 and COL4A2 mutations and in animal models with mutations in COL4A1 and COL4A2 orthologs, the pathophysiological mechanisms underlying COL4A1-related myopathy are unknown. In general, mutations are thought to impair [α1(IV)]2α2(IV) secretion. Whether pathogenesis results from intracellular retention, extracellular deficiency, or the presence of mutant proteins in basement membranes represents an important gap in knowledge and a major obstacle for developing targeted interventions. We report that Col4a1 mutant mice develop progressive neuromuscular pathology that models human disease. We demonstrate that independent muscular, neural, and vascular insults contribute to neuromyopathy and that there is mechanistic heterogeneity among tissues. Importantly, we provide evidence of a COL4A1 functional subdomain with disproportionate significance for tissue-specific pathology and demonstrate that a potential therapeutic strategy aimed at promoting [α1(IV)]2α2(IV) secretion can ameliorate or exacerbate myopathy in a mutation-dependent manner. These data have important translational implications for prediction of clinical outcomes based on genotype, development of mechanism-based interventions, and genetic stratification for clinical trials. Collectively, our data underscore the importance of the [α1(IV)]2α2(IV) network as a multifunctional signaling platform and show that allelic and tissue-specific mechanistic heterogeneities contribute to the variable expressivity of COL4A1 and COL4A2 mutations.
  • Disease-Associated Genetic Variation in Human Mitochondrial Protein Import
    • Abstract: Publication date: 2 May 2019Source: The American Journal of Human Genetics, Volume 104, Issue 5Author(s): Emmanuelle Nicolas, Rossella Tricarico, Michelle Savage, Erica A. Golemis, Michael J. HallMitochondrial dysfunction has consequences not only for cellular energy output but also for cellular signaling pathways. Mitochondrial dysfunction, often based on inherited gene variants, plays a role in devastating human conditions such as mitochondrial neuropathies, myopathies, cardiovascular disorders, and Parkinson and Alzheimer diseases. Of the proteins essential for mitochondrial function, more than 98% are encoded in the cell nucleus, translated in the cytoplasm, sorted based on the presence of encoded mitochondrial targeting sequences (MTSs), and imported to specific mitochondrial sub-compartments based on the integrated activity of a series of mitochondrial translocases, proteinases, and chaperones. This import process is typically dynamic; as cellular homeostasis is coordinated through communication between the mitochondria and the nucleus, many of the adaptive responses to stress depend on modulation of mitochondrial import. We here describe an emerging class of disease-linked gene variants that are found to impact the mitochondrial import machinery itself or to affect the proteins during their import into mitochondria. As a whole, this class of rare defects highlights the importance of correct trafficking of mitochondrial proteins in the cell and the potential implications of failed targeting on metabolism and energy production. The existence of this variant class could have importance beyond rare neuromuscular disorders, given an increasing body of evidence suggesting that aberrant mitochondrial function may impact cancer risk and therapeutic response.
  • The Convergence of Research and Clinical Genomics
    • Abstract: Publication date: 2 May 2019Source: The American Journal of Human Genetics, Volume 104, Issue 5Author(s): Ewan Birney
  • This Month in The Journal
    • Abstract: Publication date: 2 May 2019Source: The American Journal of Human Genetics, Volume 104, Issue 5Author(s): Sarah Ratzel, Sara B. Cullinan
  • Expanding the Boundaries of RNA Sequencing as a Diagnostic Tool for Rare
           Mendelian Disease
    • Abstract: Publication date: 2 May 2019Source: The American Journal of Human Genetics, Volume 104, Issue 5Author(s): Hernan D. Gonorazky, Sergey Naumenko, Arun K. Ramani, Viswateja Nelakuditi, Pouria Mashouri, Peiqui Wang, Dennis Kao, Krish Ohri, Senthuri Viththiyapaskaran, Mark A. Tarnopolsky, Katherine D. Mathews, Steven A. Moore, Andres N. Osorio, David Villanova, Dwi U. Kemaladewi, Ronald D. Cohn, Michael Brudno, James J. Dowling
  • Somatic PDGFRB Activating Variants in Fusiform Cerebral Aneurysms
    • Abstract: Publication date: Available online 25 April 2019Source: The American Journal of Human GeneticsAuthor(s): Yigit Karasozen, Joshua W. Osbun, Carolina Angelica Parada, Tina Busald, Philip Tatman, Luis F. Gonzalez-Cuyar, Christopher J. Hale, Diana Alcantara, Mark O’Driscoll, William B. Dobyns, Mitzi Murray, Louis J. Kim, Peter Byers, Michael O. Dorschner, Manuel FerreiraThe role of somatic genetic variants in the pathogenesis of intracranial-aneurysm formation is unknown. We identified a 23-year-old man with progressive, right-sided intracranial aneurysms, ipsilateral to an impressive cutaneous phenotype. The index individual underwent a series of genetic evaluations for known connective-tissue disorders, but the evaluations were unrevealing. Paired-sample exome sequencing between blood and fibroblasts derived from the diseased areas detected a single novel variant predicted to cause a p.Tyr562Cys (g.149505130T>C [GRCh37/hg19]; c.1685A>G) change within the platelet-derived growth factor receptor β gene (PDGFRB), a juxtamembrane-coding region. Variant-allele fractions ranged from 18.75% to 53.33% within histologically abnormal tissue, suggesting post-zygotic or somatic mosaicism. In an independent cohort of aneurysm specimens, we detected somatic-activating PDGFRB variants in the juxtamembrane domain or the kinase activation loop in 4/6 fusiform aneurysms (and 0/38 saccular aneurysms; Fisher’s exact test, p < 0.001). PDGFRB-variant, but not wild-type, patient cells were found to have overactive auto-phosphorylation with downstream activation of ERK, SRC, and AKT. The expression of discovered variants demonstrated non-ligand-dependent auto-phosphorylation, responsive to the kinase inhibitor sunitinib. Somatic gain-of-function variants in PDGFRB are a novel mechanism in the pathophysiology of fusiform cerebral aneurysms and suggest a potential role for targeted therapy with kinase inhibitors.
  • Mutations in ACTL6B Cause Neurodevelopmental Deficits and Epilepsy and
           Lead to Loss of Dendrites in Human Neurons
    • Abstract: Publication date: Available online 25 April 2019Source: The American Journal of Human GeneticsAuthor(s): Scott Bell, Justine Rousseau, Huashan Peng, Zahia Aouabed, Pierre Priam, Jean-Francois Theroux, Malvin Jefri, Arnaud Tanti, Hanrong Wu, Ilaria Kolobova, Heika Silviera, Karla Manzano-Vargas, Sophie Ehresmann, Fadi F. Hamdan, Nuwan Hettige, Xin Zhang, Lilit Antonyan, Christina Nassif, Lina Ghaloul-Gonzalez, Jessica SebastianWe identified individuals with variations in ACTL6B, a component of the chromatin remodeling machinery including the BAF complex. Ten individuals harbored bi-allelic mutations and presented with global developmental delay, epileptic encephalopathy, and spasticity, and ten individuals with de novo heterozygous mutations displayed intellectual disability, ambulation deficits, severe language impairment, hypotonia, Rett-like stereotypies, and minor facial dysmorphisms (wide mouth, diastema, bulbous nose). Nine of these ten unrelated individuals had the identical de novo c.1027G>A (p.Gly343Arg) mutation. Human-derived neurons were generated that recaptured ACTL6B expression patterns in development from progenitor cell to post-mitotic neuron, validating the use of this model. Engineered knock-out of ACTL6B in wild-type human neurons resulted in profound deficits in dendrite development, a result recapitulated in two individuals with different bi-allelic mutations, and reversed on clonal genetic repair or exogenous expression of ACTL6B. Whole-transcriptome analyses and whole-genomic profiling of the BAF complex in wild-type and bi-allelic mutant ACTL6B neural progenitor cells and neurons revealed increased genomic binding of the BAF complex in ACTL6B mutants, with corresponding transcriptional changes in several genes including TPPP and FSCN1, suggesting that altered regulation of some cytoskeletal genes contribute to altered dendrite development. Assessment of bi-alleic and heterozygous ACTL6B mutations on an ACTL6B knock-out human background demonstrated that bi-allelic mutations mimic engineered deletion deficits while heterozygous mutations do not, suggesting that the former are loss of function and the latter are gain of function. These results reveal a role for ACTL6B in neurodevelopment and implicate another component of chromatin remodeling machinery in brain disease.
  • Conformational Dynamics and Allosteric Regulation Landscapes of Germline
           PTEN Mutations Associated with Autism Compared to Those Associated with
    • Abstract: Publication date: Available online 18 April 2019Source: The American Journal of Human GeneticsAuthor(s): Iris Nira Smith, Stetson Thacker, Marilyn Seyfi, Feixiong Cheng, Charis EngIndividuals with germline PTEN tumor-suppressor variants have PTEN hamartoma tumor syndrome (PHTS). Clinically, PHTS has variable presentations; there are distinct subsets of PHTS-affected individuals, such as those diagnosed with autism spectrum disorder (ASD) or cancer. It remains unclear why mutations in one gene can lead to such seemingly disparate phenotypes. Therefore, we sought to determine whether it is possible to predict a given PHTS-affected individual’s a priori risk of ASD, cancer, or the co-occurrence of both phenotypes. By integrating network proximity analysis performed on the human interactome, molecular simulations, and residue-interaction networks, we demonstrate the role of conformational dynamics in the structural communication and long-range allosteric regulation of germline PTEN variants associated with ASD or cancer. We show that the PTEN interactome shares significant overlap with the ASD and cancer interactomes, providing network-based evidence that PTEN is a crucial player in the biology of both disorders. Importantly, this finding suggests that a germline PTEN variant might perturb the ASD or cancer networks differently, thus favoring one disease outcome at any one time. Furthermore, protein-dynamic structural-network analysis reveals small-world structural communication mediated by highly conserved functional residues and potential allosteric regulation of PTEN. We identified a salient structural-communication pathway that extends across the inter-domain interface for cancer-only mutations. In contrast, the structural-communication pathway is predominantly restricted to the phosphatase domain for ASD-only mutations. Our integrative approach supports the prediction and potential modulation of the relevant conformational states that influence structural communication and long-range perturbations associated with mutational effects that lead to PTEN-ASD or PTEN-cancer phenotypes.
  • A Specific CNOT1 Mutation Results in a Novel Syndrome of Pancreatic
           Agenesis and Holoprosencephaly through Impaired Pancreatic and
           Neurological Development
    • Abstract: Publication date: Available online 18 April 2019Source: The American Journal of Human GeneticsAuthor(s): Elisa De Franco, Rachel A. Watson, Wolfgang J. Weninger, Chi C. Wong, Sarah E. Flanagan, Richard Caswell, Angela Green, Catherine Tudor, Christopher J. Lelliott, Stefan H. Geyer, Barbara Maurer-Gesek, Lukas F. Reissig, Hana Lango Allen, Almuth Caliebe, Reiner Siebert, Paul Martin Holterhus, Asma Deeb, Fabrice Prin, Robert Hilbrands, Harry HeimbergWe report a recurrent CNOT1 de novo missense mutation, GenBank: NM_016284.4; c.1603C>T (p.Arg535Cys), resulting in a syndrome of pancreatic agenesis and abnormal forebrain development in three individuals and a similar phenotype in mice. CNOT1 is a transcriptional repressor that has been suggested as being critical for maintaining embryonic stem cells in a pluripotent state. These findings suggest that CNOT1 plays a critical role in pancreatic and neurological development and describe a novel genetic syndrome of pancreatic agenesis and holoprosencephaly.
  • IMPACT: Genomic Annotation of Cell-State-Specific Regulatory Elements
           Inferred from the Epigenome of Bound Transcription Factors
    • Abstract: Publication date: Available online 18 April 2019Source: The American Journal of Human GeneticsAuthor(s): Tiffany Amariuta, Yang Luo, Steven Gazal, Emma E. Davenport, Bryce van de Geijn, Kazuyoshi Ishigaki, Harm-Jan Westra, Nikola Teslovich, Yukinori Okada, Kazuhiko Yamamoto, RACI Consortium, GARNET Consortium, Alkes L. Price, Soumya RaychaudhuriDespite significant progress in annotating the genome with experimental methods, much of the regulatory noncoding genome remains poorly defined. Here we assert that regulatory elements may be characterized by leveraging local epigenomic signatures where specific transcription factors (TFs) are bound. To link these two features, we introduce IMPACT, a genome annotation strategy that identifies regulatory elements defined by cell-state-specific TF binding profiles, learned from 515 chromatin and sequence annotations. We validate IMPACT using multiple compelling applications. First, IMPACT distinguishes between bound and unbound TF motif sites with high accuracy (average AUPRC 0.81, SE 0.07; across 8 tested TFs) and outperforms state-of-the-art TF binding prediction methods, MocapG, MocapS, and Virtual ChIP-seq. Second, in eight tested cell types, RNA polymerase II IMPACT annotations capture more cis-eQTL variation than sequence-based annotations, such as promoters and TSS windows (25% average increase in enrichment). Third, integration with rheumatoid arthritis (RA) summary statistics from European (N = 38,242) and East Asian (N = 22,515) populations revealed that the top 5% of CD4+ Treg IMPACT regulatory elements capture 85.7% of RA h2, the most comprehensive explanation for RA h2 to date. In comparison, the average RA h2 captured by compared CD4+ T histone marks is 42.3% and by CD4+ T specifically expressed gene sets is 36.4%. Lastly, we find that IMPACT may be used in many different cell types to identify complex trait associated regulatory elements.
  • Defective DNA Polymerase α-Primase Leads to X-Linked Intellectual
           Disability Associated with Severe Growth Retardation, Microcephaly, and
    • Abstract: Publication date: Available online 18 April 2019Source: The American Journal of Human GeneticsAuthor(s): Hilde Van Esch, Rita Colnaghi, Kathleen Freson, Petro Starokadomskyy, Andreas Zankl, Liesbeth Backx, Iga Abramowicz, Emily Outwin, Luis Rohena, Claire Faulkner, Gary M. Leong, Ruth A. Newbury-Ecob, Rachel C. Challis, Katrin Õunap, Jacques Jaeken, Eve Seuntjens, Koen Devriendt, Ezra Burstein, Karen J. Low, Mark O’DriscollReplicating the human genome efficiently and accurately is a daunting challenge involving the duplication of upward of three billion base pairs. At the core of the complex machinery that achieves this task are three members of the B family of DNA polymerases: DNA polymerases α, δ, and ε. Collectively these multimeric polymerases ensure DNA replication proceeds at optimal rates approaching 2 × 103 nucleotides/min with an error rate of less than one per million nucleotides polymerized. The majority of DNA replication of undamaged DNA is conducted by DNA polymerases δ and ε. The DNA polymerase α-primase complex performs limited synthesis to initiate the replication process, along with Okazaki-fragment synthesis on the discontinuous lagging strand. An increasing number of human disorders caused by defects in different components of the DNA-replication apparatus have been described to date. These are clinically diverse and involve a wide range of features, including variable combinations of growth delay, immunodeficiency, endocrine insufficiencies, lipodystrophy, and cancer predisposition. Here, by using various complementary approaches, including classical linkage analysis, targeted next-generation sequencing, and whole-exome sequencing, we describe distinct missense and splice-impacting mutations in POLA1 in five unrelated families presenting with an X-linked syndrome involving intellectual disability, proportionate short stature, microcephaly, and hypogonadism. POLA1 encodes the p180 catalytic subunit of DNA polymerase α-primase. A range of replicative impairments could be demonstrated in lymphoblastoid cell lines derived from affected individuals. Our findings describe the presentation of pathogenic mutations in a catalytic component of a B family DNA polymerase member, DNA polymerase α.
  • A Transient Pulse of Genetic Admixture from the Crusaders in the Near East
           Identified from Ancient Genome Sequences
    • Abstract: Publication date: Available online 18 April 2019Source: The American Journal of Human GeneticsAuthor(s): Marc Haber, Claude Doumet-Serhal, Christiana L. Scheib, Yali Xue, Richard Mikulski, Rui Martiniano, Bettina Fischer-Genz, Holger Schutkowski, Toomas Kivisild, Chris Tyler-SmithDuring the medieval period, hundreds of thousands of Europeans migrated to the Near East to take part in the Crusades, and many of them settled in the newly established Christian states along the Eastern Mediterranean coast. Here, we present a genetic snapshot of these events and their aftermath by sequencing the whole genomes of 13 individuals who lived in what is today known as Lebanon between the 3rd and 13th centuries CE. These include nine individuals from the “Crusaders’ pit” in Sidon, a mass burial in South Lebanon identified from the archaeology as the grave of Crusaders killed during a battle in the 13th century CE. We show that all of the Crusaders’ pit individuals were males; some were Western Europeans from diverse origins, some were locals (genetically indistinguishable from present-day Lebanese), and two individuals were a mixture of European and Near Eastern ancestries, providing direct evidence that the Crusaders admixed with the local population. However, these mixtures appear to have had limited genetic consequences since signals of admixture with Europeans are not significant in any Lebanese group today—in particular, Lebanese Christians are today genetically similar to local people who lived during the Roman period which preceded the Crusades by more than four centuries.
  • CCR4-NOT transcription complex, subunit 1 (CNOT1) Variant Associated with
    • Abstract: Publication date: Available online 18 April 2019Source: The American Journal of Human GeneticsAuthor(s): Paul Kruszka, Seth I. Berger, Karin Weiss, Joshua L. Everson, Ariel F. Martinez, Sungkook Hong, Kwame Anyane-Yeboa, Robert J. Lipinski, Maximilian MuenkeHoloprosencephaly is the incomplete separation of the forebrain during embryogenesis. Both genetic and environmental etiologies have been determined for holoprosencephaly; however, a genetic etiology is not found in most cases. In this report, we present two unrelated individuals with semilobar holoprosencephaly who have the identical de novo missense variant in the gene CCR4-NOT transcription complex, subunit 1 (CNOT1). The variant (c.1603C>T [p.Arg535Cys]) is predicted to be deleterious and is not present in public databases. CNOT1 has not been previously associated with holoprosencephaly or other brain malformations. In situ hybridization analyses of mouse embryos show that Cnot1 is expressed in the prosencephalic neural folds at gestational day 8.25 during the critical period for subsequent forebrain division. Combining human and mouse data, we show that CNOT1 is associated with incomplete forebrain division.
  • Dynamic Scan Procedure for Detecting Rare-Variant Association Regions in
           Whole-Genome Sequencing Studies
    • Abstract: Publication date: Available online 12 April 2019Source: The American Journal of Human GeneticsAuthor(s): Zilin Li, Xihao Li, Yaowu Liu, Jincheng Shen, Han Chen, Hufeng Zhou, Alanna C. Morrison, Eric Boerwinkle, Xihong LinWhole-genome sequencing (WGS) studies are being widely conducted in order to identify rare variants associated with human diseases and disease-related traits. Classical single-marker association analyses for rare variants have limited power, and variant-set-based analyses are commonly used by researchers for analyzing rare variants. However, existing variant-set-based approaches need to pre-specify genetic regions for analysis; hence, they are not directly applicable to WGS data because of the large number of intergenic and intron regions that consist of a massive number of non-coding variants. The commonly used sliding-window method requires the pre-specification of fixed window sizes, which are often unknown as a priori, are difficult to specify in practice, and are subject to limitations given that the sizes of genetic-association regions are likely to vary across the genome and phenotypes. We propose a computationally efficient and dynamic scan-statistic method (Scan the Genome [SCANG]) for analyzing WGS data; this method flexibly detects the sizes and the locations of rare-variant association regions without the need to specify a prior, fixed window size. The proposed method controls for the genome-wise type I error rate and accounts for the linkage disequilibrium among genetic variants. It allows the detected sizes of rare-variant association regions to vary across the genome. Through extensive simulated studies that consider a wide variety of scenarios, we show that SCANG substantially outperforms several alternative methods for detecting rare-variant-associations while controlling for the genome-wise type I error rates. We illustrate SCANG by analyzing the WGS lipids data from the Atherosclerosis Risk in Communities (ARIC) study.
  • Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive
    • Abstract: Publication date: Available online 11 April 2019Source: The American Journal of Human GeneticsAuthor(s): Kathleen M. Gorman, Esther Meyer, Detelina Grozeva, Egidio Spinelli, Amy McTague, Alba Sanchis-Juan, Keren J. Carss, Emily Bryant, Adi Reich, Amy L. Schneider, Ronit M. Pressler, Michael A. Simpson, Geoff D. Debelle, Evangeline Wassmer, Jenny Morton, Diana Sieciechowicz, Eric Jan-Kamsteeg, Alex R. Paciorkowski, Mary D. King, J. Helen CrossThe occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.
  • The Metabolic Map into the Pathomechanism and Treatment of PGM1-CDG
    • Abstract: Publication date: Available online 11 April 2019Source: The American Journal of Human GeneticsAuthor(s): Silvia Radenkovic, Matthew J. Bird, Tim L. Emmerzaal, Sunnie Y. Wong, Catarina Felgueira, Kyle M. Stiers, Leila Sabbagh, Nastassja Himmelreich, Gernot Poschet, Petra Windmolders, Jan Verheijen, Peter Witters, Ruqaiah Altassan, Tomas Honzik, Tuba F. Eminoglu, Phillip M. James, Andrew C. Edmondson, Jozef Hertecant, Tamas Kozicz, Christian ThielPhosphoglucomutase 1 (PGM1) encodes the metabolic enzyme that interconverts glucose-6-P and glucose-1-P. Mutations in PGM1 cause impairment in glycogen metabolism and glycosylation, the latter manifesting as a congenital disorder of glycosylation (CDG). This unique metabolic defect leads to abnormal N-glycan synthesis in the endoplasmic reticulum (ER) and the Golgi apparatus (GA). On the basis of the decreased galactosylation in glycan chains, galactose was administered to individuals with PGM1-CDG and was shown to markedly reverse most disease-related laboratory abnormalities. The disease and treatment mechanisms, however, have remained largely elusive. Here, we confirm the clinical benefit of galactose supplementation in PGM1-CDG-affected individuals and obtain significant insights into the functional and biochemical regulation of glycosylation. We report here that, by using tracer-based metabolomics, we found that galactose treatment of PGM1-CDG fibroblasts metabolically re-wires their sugar metabolism, and as such replenishes the depleted levels of galactose-1-P, as well as the levels of UDP-glucose and UDP-galactose, the nucleotide sugars that are required for ER- and GA-linked glycosylation, respectively. To this end, we further show that the galactose in UDP-galactose is incorporated into mature, de novo glycans. Our results also allude to the potential of monosaccharide therapy for several other CDG.
  • Homozygous Mutations in CSF1R Cause a Pediatric-Onset Leukoencephalopathy
           and Can Result in Congenital Absence of Microglia
    • Abstract: Publication date: Available online 11 April 2019Source: The American Journal of Human GeneticsAuthor(s): Nynke Oosterhof, Irene J. Chang, Ehsan Ghayoor Karimiani, Laura E. Kuil, Dana M. Jensen, Ray Daza, Erica Young, Lee Astle, Herma C. van der Linde, Giridhar M. Shivaram, Jeroen Demmers, Caitlin S. Latimer, C. Dirk Keene, Emily Loter, Reza Maroofian, Tjakko J. van Ham, Robert F. Hevner, James T. BennettMicroglia are CNS-resident macrophages that scavenge debris and regulate immune responses. Proliferation and development of macrophages, including microglia, requires Colony Stimulating Factor 1 Receptor (CSF1R), a gene previously associated with a dominant adult-onset neurological condition (adult-onset leukoencephalopathy with axonal spheroids and pigmented glia). Here, we report two unrelated individuals with homozygous CSF1R mutations whose presentation was distinct from ALSP. Post-mortem examination of an individual with a homozygous splice mutation (c.1754−1G>C) demonstrated several structural brain anomalies, including agenesis of corpus callosum. Immunostaining demonstrated almost complete absence of microglia within this brain, suggesting that it developed in the absence of microglia. The second individual had a homozygous missense mutation (c.1929C>A [p.His643Gln]) and presented with developmental delay and epilepsy in childhood. We analyzed a zebrafish model (csf1rDM) lacking Csf1r function and found that their brains also lacked microglia and had reduced levels of CUX1, a neuronal transcription factor. CUX1+ neurons were also reduced in sections of homozygous CSF1R mutant human brain, identifying an evolutionarily conserved role for CSF1R signaling in production or maintenance of CUX1+ neurons. Since a large fraction of CUX1+ neurons project callosal axons, we speculate that microglia deficiency may contribute to agenesis of the corpus callosum via reduction in CUX1+ neurons. Our results suggest that CSF1R is required for human brain development and establish the csf1rDM fish as a model for microgliopathies. In addition, our results exemplify an under-recognized form of phenotypic expansion, in which genes associated with well-recognized, dominant conditions produce different phenotypes when biallelically mutated.
  • Pathogenic Variants in GPC4 Cause Keipert Syndrome
    • Abstract: Publication date: Available online 11 April 2019Source: The American Journal of Human GeneticsAuthor(s): David J. Amor, Sarah E.M. Stephenson, Mirna Mustapha, Martin A. Mensah, Charlotte W. Ockeloen, Wei Shern Lee, Rick M. Tankard, Dean G. Phelan, Marwan Shinawi, Arjan P.M. de Brouwer, Rolph Pfundt, Cari Dowling, Tomi L. Toler, V. Reid Sutton, Emanuele Agolini, Martina Rinelli, Rossella Capolino, Diego Martinelli, Giuseppe Zampino, Miroslav DumićGlypicans are a family of cell-surface heparan sulfate proteoglycans that regulate growth-factor signaling during development and are thought to play a role in the regulation of morphogenesis. Whole-exome sequencing of the Australian family that defined Keipert syndrome (nasodigitoacoustic syndrome) identified a hemizygous truncating variant in the gene encoding glypican 4 (GPC4). This variant, located in the final exon of GPC4, results in premature termination of the protein 51 amino acid residues prior to the stop codon, and in concomitant loss of functionally important N-linked glycosylation (Asn514) and glycosylphosphatidylinositol (GPI) anchor (Ser529) sites. We subsequently identified seven affected males from five additional kindreds with novel and predicted pathogenic variants in GPC4. Segregation analysis and X-inactivation studies in carrier females provided supportive evidence that the GPC4 variants caused the condition. Furthermore, functional studies of recombinant protein suggested that the truncated proteins p.Gln506∗ and p.Glu496∗ were less stable than the wild type. Clinical features of Keipert syndrome included a prominent forehead, a flat midface, hypertelorism, a broad nose, downturned corners of mouth, and digital abnormalities, whereas cognitive impairment and deafness were variable features. Studies of Gpc4 knockout mice showed evidence of the two primary features of Keipert syndrome: craniofacial abnormalities and digital abnormalities. Phylogenetic analysis demonstrated that GPC4 is most closely related to GPC6, which is associated with a bone dysplasia that has a phenotypic overlap with Keipert syndrome. Overall, we have shown that pathogenic variants in GPC4 cause a loss of function that results in Keipert syndrome, making GPC4 the third human glypican to be linked to a genetic syndrome.
  • Bi-allelic CSF1R Mutations Cause Skeletal Dysplasia of
           Dysosteosclerosis-Pyle Disease Spectrum and Degenerative Encephalopathy
           with Brain Malformation
    • Abstract: Publication date: Available online 11 April 2019Source: The American Journal of Human GeneticsAuthor(s): Long Guo, Débora Romeo Bertola, Asako Takanohashi, Asuka Saito, Yuko Segawa, Takanori Yokota, Satoru Ishibashi, Yoichiro Nishida, Guilherme Lopes Yamamoto, José Francisco da Silva Franco, Rachel Sayuri Honjo, Chong Ae Kim, Camila Manso Musso, Margaret Timmons, Amy Pizzino, Ryan J. Taft, Bryan Lajoie, Melanie A. Knight, Kenneth H. Fischbeck, Andrew B. SingletonColony stimulating factor 1 receptor (CSF1R) plays key roles in regulating development and function of the monocyte/macrophage lineage, including microglia and osteoclasts. Mono-allelic mutations of CSF1R are known to cause hereditary diffuse leukoencephalopathy with spheroids (HDLS), an adult-onset progressive neurodegenerative disorder. Here, we report seven affected individuals from three unrelated families who had bi-allelic CSF1R mutations. In addition to early-onset HDLS-like neurological disorders, they had brain malformations and skeletal dysplasia compatible to dysosteosclerosis (DOS) or Pyle disease. We identified five CSF1R mutations that were homozygous or compound heterozygous in these affected individuals. Two of them were deep intronic mutations resulting in abnormal inclusion of intron sequences in the mRNA. Compared with Csf1r-null mice, the skeletal and neural phenotypes of the affected individuals appeared milder and variable, suggesting that at least one of the mutations in each affected individual is hypomorphic. Our results characterized a unique human skeletal phenotype caused by CSF1R deficiency and implied that bi-allelic CSF1R mutations cause a spectrum of neurological and skeletal disorders, probably depending on the residual CSF1R function.
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