Case Reports in Genetics
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Open Access journal
ISSN (Print) 2090-6544 - ISSN (Online) 2090-6552
Published by Hindawi [333 journals]
- Pathogenic Variant in ACTB, p.Arg183Trp, Causes Juvenile-Onset Dystonia,
Hearing Loss, and Developmental Delay without Midline Malformation
Abstract: ACTB encodes the β-actin, and pathogenic variations in this gene have typically been associated with Baraitser-Winter cerebrofrontofacial syndrome, a congenital malformation syndrome characterized by short stature, craniofacial anomalies, and cerebral anomalies. Here, we describe the third case with the p.Arg183Trp variant in ACTB causing juvenile-onset dystonia. Our patient has severe, intractable dystonia, developmental delay, and sensorineural hearing loss, besides hyperintensities in the caudate nuclei and putamen on the brain MRI, which is a distinct but overlapping phenotype with the previously reported case of identical twins with the same alteration in ACTB.
PubDate: Wed, 12 Apr 2017 09:24:24 +000
- Respiratory Failure due to Severe Obesity and Kyphoscoliosis in a
24-Year-Old Male with Molecularly Confirmed Prader-Willi Syndrome in
Tertiary Hospital in Northern Tanzania
Abstract: Obesity, mild intellectual disability, hypotonia, poor sucking, cryptorchidism in males, hypogonadism, and kyphoscoliosis are common features of Prader-Willi syndrome (PWS). We report a case who had severe respiratory complications due to extreme obesity and kyphoscoliosis, which are important causes of morbidity and mortality, and discuss management. Furthermore, this is the first molecularly confirmed PWS case in Sub-Saharan Africa outside South Africa.
PubDate: Sun, 09 Apr 2017 00:00:00 +000
- Prenatal Diagnosis of a 2.5 Mb De Novo 17q24.1q24.2 Deletion
Encompassing KPNA2 and PSMD12 Genes in a Fetus with Craniofacial
Dysmorphism, Equinovarus Feet, and Syndactyly
Abstract: Interstitial 17q24.1 or 17q24.2 deletions were reported after conventional cytogenetic analysis or chromosomal microarray analysis in patients presenting intellectual disability, facial dysmorphism, and/or malformations. We report on a fetus with craniofacial dysmorphism, talipes equinovarus, and syndactyly associated with a de novo 2.5 Mb 17q24.1q24.2 deletion. Among the deleted genes, KPNA2 and PSMD12 are discussed for the correlation with the fetal phenotype. This is the first case of prenatal diagnosis of 17q24.1q24.2 deletion.
PubDate: Wed, 29 Mar 2017 06:58:47 +000
- Three Novel Mutations in the NPHS1 Gene in Vietnamese Patients with
Congenital Nephrotic Syndrome
Abstract: Congenital nephrotic syndrome, a rare and severe disease, is inherited as an autosomal recessive trait. The disease manifests shortly after birth and occurs predominantly in families of Finnish origin but has now been observed in all countries and races. Mutations in the NPHS1 gene, which encodes nephrin, are the main causes of congenital nephrotic syndrome in patients. In this study, we report the first mutational analysis of the NPHS1 gene in three unrelated children from three different Vietnamese families. These patients were examined and determined to be suffering from congenital nephrotic syndrome in the Department of Pediatrics, Vietnam National Hospital of Pediatrics. All 29 exons and exon-intron boundaries of NPHS1 were analyzed by PCR and DNA sequencing. Genetic analysis of the NPHS1 gene revealed one compound heterozygous variant p.Glu117Lys, one heterozygous missense mutation p.Asp310Asn, and one heterozygous frame-shifting mutation (c.3250_3251insG causing p.Val1084Glyfs12) in patient 1. In patient 2, one heterozygous variant p.Glu117Lys and one novel heterozygous missense mutation p.Ser324Ala were identified. Finally, a novel missense mutation p.Arg802Leu and a novel nonsense mutation (c.2442C>G causing p.K792) were identified in patient 3.
PubDate: Tue, 14 Mar 2017 00:00:00 +000
- Goldenhar Syndrome with Dextrocardia and Right Pulmonary Hypoplasia: An
Abstract: Goldenhar syndrome (GS), a rare condition, occurring due to defect in development of first and second branchial arches, is characterized by a combination of various anomalies involving face, eyes, ears, vertebrae, heart, and lungs. The etiology of GS is not fully known, although various hypotheses have been proposed along with its genetic association and many other causes. Facial asymmetry and hypoplasia of the mandible are characteristic features of GS along with microtia and preauricular appendages and pits. Dextrocardia or pulmonary hypoplasia in GS has previously been reported separately. We report a 7-year-old female child of GS with combination of anomalies, dextrocardia, and pulmonary hypoplasia, which is a rare association.
PubDate: Thu, 09 Mar 2017 08:13:47 +000
- Urea Cycle Defects: Early-Onset Disease Associated with A208T Mutation in
OTC Gene—Expanding the Clinical Phenotype
Abstract: Ornithine transcarbamylase deficiency (OMIM: 311250) is the most common disorder of urea cycle disorders, accounting for nearly 50% of all cases. We report a case of a two-month- old male patient, who attends our medical genetics consultation because of low citrulline levels and elevated glutamine to citrulline ratio detected by expanded newborn screening with tandem mass spectrometry. He is an asymptomatic male with a normal physical examination and appropriate neurodevelopmental milestones. The patient has a family history of one older brother who died at 18 months old from severe and sudden hyperammonemia and a maternal aunt who suddenly died at two years old. He had high plasma ammonium concentration and a confirmed OTC mutation (p.A208T). Usually, this mutation causes OTC deficiency of late onset in adult males. However, this report raises awareness about mutations previously described as a late-onset causing disease, which can cause severe hyperammonemia and high risk of dying at an early age.
PubDate: Sun, 05 Feb 2017 07:40:42 +000
- A Newborn with Panhypopituitarism and Seizures
Abstract: Interstitial deletions on the short arm of chromosome 20 are uncommon, and therefore the clinical phenotype is poorly defined. Very few cases have been reported in the literature so far. In this report, we describe a 4-month-old female with a heterozygous deletion at 20p11.21p12.1 with panhypopituitarism and cardiac, gastrointestinal, and genitourinary anomalies along with dysmorphic facial features. We compared and discussed similar cases with overlapping deletions in 20p11 region. We wish to report this rare occurrence as this may better define the phenotypes of the 20p interstitial deletion with certain dysmorphic features, multiorgan involvement, and related clinical characteristics in this patient population.
PubDate: Wed, 01 Feb 2017 09:51:23 +000
- Costello Syndrome and Umbilical Ligament Rhabdomyosarcoma in Two Pediatric
Patients: Case Reports and Review of the Literature
Abstract: Costello syndrome is caused by heterozygous de novo missense mutations in the protooncogene HRAS with tumor predisposition, especially rhabdomyosarcoma. We here report two pediatric patients with Costello syndrome and umbilical ligament rhabdomyosarcoma. A review of the literature published in English in MEDLINE from January 1971 to June 2016 using the search terms “Costello syndrome” and “rhabdomyosarcoma” was performed, including two new cases that we describe. Twenty-six patients with Costello syndrome and rhabdomyosarcoma were recorded with mean age of diagnosis of 2 years and 8 months. The most common tumor location was the abdomen/pelvis, including four out of ten of those in the umbilical ligament. The most common histological subtype was embryonal rhabdomyosarcoma. Overall survival was 43%. A total of 17 rhabdomyosarcomas in pediatric patients arising in the umbilical ligament were recorded with mean age of diagnosis of 3 years and 4 months. Overall survival was 69%. Costello syndrome is a poorly known disorder in pediatric oncology but their predisposition to malignancies implies the need for a new perspective on early diagnosis and aggressive medical and surgical treatment.
PubDate: Thu, 19 Jan 2017 00:00:00 +000
- Novel Pathogenic Variant in TGFBR2 Confirmed by Molecular Modeling Is a
Rare Cause of Loeys-Dietz Syndrome
Abstract: Loeys-Dietz syndrome (LDS) is a connective tissue disorder characterized by vascular findings of aneurysm and/or dissection of cerebral, thoracic, or abdominal arteries and skeletal findings. We report a case of a novel pathogenic variant in TGFBR2 and phenotype consistent with classic LDS. The proband was a 10-year-old presenting to the genetics clinic with an enlarged aortic root (Z-scores 5-6), pectus excavatum, and congenital contractures of the right 2nd and 3rd digit. Molecular testing of TGFBR2 was sent to a commercial laboratory and demonstrated a novel, likely pathogenic, variant in exon 4, c.1061T>C, p.(L354P). Molecular modeling reveals alteration of local protein structure as a result of this pathogenic variant. This pathogenic variant has not been previously reported in LDS and thus expands the pathogenic variant spectrum of this condition.
PubDate: Mon, 09 Jan 2017 14:31:41 +000
- Further Evidence That the CFTR Variant c.2620-6T>C Is Benign
Abstract: The c.2620-6T>C variant in the CFTR gene is a rare variant about which little is known. We present an asymptomatic adult who has this variant as well as the well described delta F508 pathogenic variant in transpresentation. This patient provides additional evidence that this is a benign polymorphism.
PubDate: Mon, 09 Jan 2017 06:26:41 +000
- Familial Case of Pelizaeus-Merzbacher Disorder Detected by Oligoarray
Comparative Genomic Hybridization: Genotype-to-Phenotype Diagnosis
Abstract: Introduction. Pelizaeus-Merzbacher disease (PMD) is an X-linked recessive hypomyelinating leukodystrophy characterized by nystagmus, spastic quadriplegia, ataxia, and developmental delay. It is caused by mutation in the PLP1 gene. Case Description. We report a 9-year-old boy referred for oligoarray comparative genomic hybridization (OA-CGH) because of intellectual delay, seizures, microcephaly, nystagmus, and spastic paraplegia. Similar clinical findings were reported in his older brother and maternal uncle. Both parents had normal phenotypes. OA-CGH was performed and a 436 Kb duplication was detected and the diagnosis of PMD was made. The mother was carrier of this 436 Kb duplication. Conclusion. Clinical presentation has been accepted as being the mainstay of diagnosis for most conditions. However, recent developments in genetic diagnosis have shown that, in many congenital and sporadic disorders lacking specific phenotypic manifestations, a genotype-to-phenotype approach can be conclusive. In this case, a diagnosis was reached by universal genomic testing, namely, whole genomic array.
PubDate: Wed, 04 Jan 2017 07:00:24 +000
- An Interstitial Deletion at 7q33-36.1 in a Patient with Intellectual
Disability, Significant Language Delay, and Severe Microcephaly
Abstract: Interstitial deletions of the distal 7q region are considered a rare entity. In this report, we describe a seven-year-old male with a heterozygous interstitial deletion at 7q33-36.1 with characteristic dysmorphic facial features, intellectual disability, severe microcephaly, and significant language delay. The primary focus of our report is to compare our case with the few others in the literature describing interstitial deletions at the long arm of chromosome 7. Based on the various breakpoints in prior studies, a number of phenotypic variations have been identified that are unique to each of the reports. However, there are also a number of similarities among these cases as well. We hope to provide a concise review of the literature and genes involved within our deletion sequence in the hope that it will contribute to creating a phenotypic profile for this patient population.
PubDate: Thu, 08 Dec 2016 11:58:25 +000
- Ring Chromosome 4 in a Child with Multiple Congenital Abnormalities: A
Case Report and Review of the Literature
Abstract: A female child born preterm with intrauterine growth retardation and presenting with facial dysmorphism with clefts, microcephaly, limb deformities, and congenital abnormalities involving cardiovascular and urinary systems is described. Chromosomal analysis showed a de novo 46,XX,r(4)(p15.3q35) karyotype. The clinical features of the patient were compared with the phenotypic characteristics of 17 previously reported cases with ring chromosome 4 and those with Wolf-Hirschhorn syndrome (4p-). Clinical features observed in this case are consistent with the consensus phenotype in ring chromosome 4. Patent ductus arteriosus and bilateral talipes equinovarus observed in this baby widen the phenotypic spectrum associated with ring chromosome 4.
PubDate: Tue, 16 Aug 2016 09:16:10 +000
- Adult Prader-Willi Syndrome: An Update on Management
Abstract: With the advancement of medical care, the survival of most patients with syndromal genetic disease is greatly improved. In this case report, we have reported an adult Prader-Willi syndrome patient who is being diagnosed at the age of 33. The clinical features and their associated complications during adulthood have been reviewed.
PubDate: Wed, 08 Jun 2016 11:57:41 +000
- Multiple Coronary Artery Microfistulas in a Girl with Kleefstra Syndrome
Abstract: Kleefstra syndrome is characterized by hypotonia, developmental delay, dysmorphic features, congenital heart defects, and so forth. It is caused by 9q34.3 microdeletions or EHMT1 mutations. Herein a 20-month-old girl with Kleefstra syndrome, due to a de novo subterminal deletion, is described. She exhibits a rare and complex cardiopathy, encompassing multiple coronary artery microfistulas, VSD/ASD, and PFO.
PubDate: Sat, 30 Apr 2016 07:50:53 +000
- Whole Exome Sequencing Leading to the Diagnosis of Dysferlinopathy with a
Novel Missense Mutation (c.959G>C)
Abstract: Dysferlinopathy is an uncommon, progressive muscular dystrophy that has a wide phenotypic variability and primarily supportive management (Nguyen et al., 2007; Narayanaswami et al., 2014). Amyloid myopathy is a distinct, rare disorder that can present similarly to inflammatory myopathies and requires a high clinical suspicion for early intervention to prolong survival. Amyloid myopathy is typically associated with other systemic manifestations of amyloidosis, but rare cases of isolated amyloid myopathy have been described (Mandl et al., 2000; Hull et al., 2001). Positive Congo red stains on tissue biopsy remain the gold standard for diagnosis (Spuler et al., 1998; Karacostas et al., 2005). A high clinical suspicion and meticulous diagnostic workup that includes novel techniques are necessary for identifying these rare disorders. We report a middle-aged man with progressive leg muscle weakness who was initially treated as having amyloid myopathy but was later diagnosed as having dysferlinopathy by Whole Exome Sequencing (WES) analysis. We also report a novel missense mutation (c.959G>C) to help correlate in any patient with presumed dysferlinopathy and to add to the already known genotype of this disorder.
PubDate: Tue, 19 Apr 2016 06:03:51 +000
- Novel GLA Deletion in a Cypriot Female Presenting with Cornea Verticillata
Abstract: Fabry disease is an X-linked lysosomal storage disorder resulting from a deficiency of the hydrolytic enzyme α-galactosidase A (α-Gal-A). It is characterized by progressive lysosomal accumulation of globotriaosylceramide (Gb3) and multisystem pathology, affecting the skin, nervous and cerebrovascular systems, kidneys, and heart. Heterozygous females typically exhibit milder symptoms and a later age of onset than males. Rarely, they may be relatively asymptomatic throughout a normal life span or may have symptoms as severe as those observed in males with the classic phenotype. We report on a 17-year-old female in whom cornea verticillata was found during a routine ophthalmological examination but with no other clinical symptoms. Leucocyte α-galactosidase activity was within the overlap range between Fabry heterozygotes and normal controls. Sanger sequencing of the GLA gene failed to reveal any pathogenic variants. Multiplex Ligation-dependent Probe Amplification (MLPA) analysis revealed a deletion of exon 7. Using a long-range PCR walking approach, we managed to identify the deletion breakpoints. The deletion spans 1182 bp, with its 5′ end located within exon 6 of the GLA gene and its 3′ end located 612 bp downstream of exon 7. This finding represents a novel deletion identified in the first reported Cypriot female carrier of Fabry disease.
PubDate: Wed, 30 Mar 2016 13:20:19 +000
- Early Infantile Epileptic Encephalopathy in an STXBP1 Patient with Lactic
Acidemia and Normal Mitochondrial Respiratory Chain Function
Abstract: A wide range of clinical findings have been associated with mutations in Syntaxin Binding Protein 1 (STXBP1), including multiple forms of epilepsy, nonsyndromic intellectual disability, and movement disorders. STXBP1 mutations have recently been associated with mitochondrial pathology, although it remains unclear if this phenotype is a part of the core feature for this gene disorder. We report a 7-year-old boy who presented for diagnostic evaluation of intractable epilepsy, episodic ataxia, resting tremor, and speech regression following a period of apparently normal early development. Mild lactic acidemia was detected on one occasion at the time of an intercurrent illness. Due to the concern for mitochondrial disease, ophthalmologic evaluation was performed that revealed bilateral midperiphery pigmentary mottling. Optical coherence tomography (OCT) testing demonstrated a bilaterally thickened ganglion cell layer in the perifovea. Skeletal muscle biopsy analysis showed no mitochondrial abnormalities or respiratory chain dysfunction. Exome sequencing identified a de novo c.1651C>T (p.R551C) mutation in STXBP1. Although mitochondrial dysfunction has been reported in some individuals, our proband had only mild lactic acidemia and no skeletal muscle tissue evidence of mitochondrial disease pathology. Thus, mitochondrial dysfunction is not an obligate feature of STXBP1 disease.
PubDate: Wed, 16 Mar 2016 07:27:54 +000
- False Negative Cell-Free DNA Screening Result in a Newborn with Trisomy 13
Abstract: Background. Noninvasive prenatal screening (NIPS) is revolutionizing prenatal screening as a result of its increased sensitivity, specificity. NIPS analyzes cell-free fetal DNA (cffDNA) circulating in maternal plasma to detect fetal chromosome abnormalities. However, cffDNA originates from apoptotic placental trophoblast; therefore cffDNA is not always representative of the fetus. Although the published data for NIPS testing states that the current technique ensures high sensitivity and specificity for aneuploidy detection, false positives are possible due to isolated placental mosaicism, vanishing twin or cotwin demise, and maternal chromosome abnormalities or malignancy. Results. We report a case of false negative cell-free DNA (cfDNA) screening due to fetoplacental mosaicism. An infant male with negative cfDNA screening result was born with multiple congenital abnormalities. Postnatal chromosome and FISH studies on a blood specimen revealed trisomy 13 in 20/20 metaphases and 100% interphase nuclei, respectively. FISH analysis on tissues collected after delivery revealed extraembryonic mosaicism. Conclusions. Extraembryonic tissue mosaicism is likely responsible for the false negative cfDNA screening result. This case illustrates that a negative result does not rule out the possibility of a fetus affected with a trisomy, as cffDNA is derived from the placenta and therefore may not accurately represent the fetal genetic information.
PubDate: Mon, 22 Feb 2016 07:00:29 +000
- De Novo Interstitial Microdeletion at 1q32.1 in a 10-Year-Old Boy with
Developmental Delay and Dysmorphism
Abstract: A 10-year-old boy was referred with developmental delay and dysmorphism. Genomewide aCGH microarray analysis detected a de novo 3.7 Mb deletion at 1q32.1: arr 1q32.1(199,985,888-203,690,832)x1 dn [build HG19]. This first report of a deletion in this region implies a critical role for dosage-sensitive genes within 1q32.1 in neurological development. This is consistent with previously reported duplications of this region in patients with a similar phenotype.
PubDate: Wed, 03 Feb 2016 09:14:53 +000
- De Novo Trisomy 1q10q23.3 Mosaicism Causes Microcephaly, Severe
Developmental Delay, and Facial Dysmorphic Features but No Cardiac
Abstract: Proximal duplications of chromosome 1q are rare chromosomal abnormalities. Most patients with this condition present with neurological, urogenital, and congenital heart disease and short life expectancy. Mosaicism for trisomy 1q10q23.3 has only been reported once in the literature. Here we discuss a second case: a girl with a postnatal diagnosis of a de novo pure mosaic trisomy 1q1023.3 who has no urogenital or cardiac anomalies.
PubDate: Sun, 31 Jan 2016 13:01:01 +000
- Angelman-Like Syndrome: A Genetic Approach to Diagnosis with Illustrative
Abstract: Epigenetic abnormalities in 15q11-13 imprinted region and UBE3A mutation are the two major mechanisms for molecularly confirmed Angelman Syndrome. However, there is 10% of clinically diagnosed Angelman Syndrome remaining test negative. With the advancement of genomic technology like array comparative genomic hybridization and next generation sequencing methods, it is found that some patients of these test negative Angelman-like Syndromes actually have alternative diagnoses. Accurate molecular diagnosis is paramount for genetic counseling and subsequent management. Despite overlapping phenotypes between Angelman and Angelman-like Syndrome, there are some subtle but distinct features which could differentiate them clinically. It would provide important clue during the diagnostic process for clinicians.
PubDate: Thu, 28 Jan 2016 14:06:43 +000
- Osteoporosis-Pseudoglioma in a Mauritanian Child due to a Novel Mutation
Abstract: Osteoporosis-pseudoglioma (OPPG) syndrome is a very rare autosomal recessive disorder, caused by mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene. It manifests by severe juvenile osteoporosis with congenital or infancy-onset visual loss. We describe a case of OPPG due to novel mutation in LRP5 gene, occurring in a female Mauritanian child. This 10-year-old female child was born blind, and after then multiple fragility fractures appeared. PCR amplification and sequencing revealed a novel homozygous nonsense mutation in exon 10 of the LRP5 gene (c.2270G>A; ); this mutation leads to the production of a truncated protein containing 757 amino acids instead of 1615, located in the third β-propeller domain of the LRP5 protein. Both parents were heterozygous for the mutation. This is the first case of the OPPG described in black Africans, which broadens the spectrum of LRP5 gene mutations in OPPG.
PubDate: Tue, 19 Jan 2016 09:15:59 +000
- A Novel Nonsense Mutation of the AGL Gene in a Romanian Patient with
Glycogen Storage Disease Type IIIa
Abstract: Background. Glycogen storage disease type III (GSDIII) is a rare metabolic disorder with autosomal recessive inheritance, caused by deficiency of the glycogen debranching enzyme. There is a high phenotypic variability due to different mutations in the AGL gene. Methods and Results. We describe a 2.3-year-old boy from a nonconsanguineous Romanian family, who presented with severe hepatomegaly with fibrosis, mild muscle weakness, cardiomyopathy, ketotic fasting hypoglycemia, increased transaminases, creatine phosphokinase, and combined hyperlipoproteinemia. GSD type IIIa was suspected. Accordingly, genomic DNA of the index patient was analyzed by next generation sequencing of the AGL gene. For confirmation of the two mutations found, genetic analysis of the parents and grandparents was also performed. The patient was compound heterozygous for the novel mutation c.3235C>T, p.Gln107 (exon 24) and the known mutation c.1589C>G, p.Ser53 (exon 12). c.3235 >T, p.Gln107 was inherited from the father, who inherited it from his mother. c.1589C>G, p.Ser53 was inherited from the mother, who inherited it from her father. Conclusion. We report the first genetically confirmed case of a Romanian patient with GSDIIIa. We detected a compound heterozygous genotype with a novel mutation, in the context of a severe hepatopathy and an early onset of cardiomyopathy.
PubDate: Sun, 17 Jan 2016 08:29:29 +000
- Early Morphokinetic Monitoring of Embryos after Intracytoplasmic Sperm
Injection with Fresh Ejaculate Sperm in Nonmosaic Klinefelter Syndrome: A
Abstract: The patient was diagnosed with nonmosaic 47, XXY Klinefelter Syndrome with the AZF deletion absent and SRY+. The nonmosaic 47, XXY karyotype was confirmed on a skin biopsy chromosomal analysis. Using only ejaculate motile sperms, 11 oocytes underwent ICSI and were placed rapidly in a time lapse (Embryoscope ©) with a specific culture dish. Biopsies were performed on six embryos on the 3rd day, and numerical chromosomal abnormalities were observed using the FISH test before transfer. PGS results were normal in only two embryos with normal morphokinetics in the Embryoscope. For clinical confirmation of pregnancy, ultrasonographic examination was performed during the 7th week of pregnancy, and two gestational sacs and fetal heart beat were observed.
PubDate: Wed, 30 Dec 2015 09:41:40 +000
- Intermediate MCAD Deficiency Associated with a Novel Mutation of the ACADM
Abstract: Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is an autosomal recessive disorder that leads to a defect in fatty acid oxidation. ACADM is the only candidate gene causing MCAD deficiency. A single nucleotide change, c.985A>G, occurring at exon 11 of the ACADM gene, is the most prevalent mutation. In this study, we report a Caucasian family with multiple MCADD individuals. DNA sequence analysis of the ACADM gene performed in this family revealed that two family members showing mild MCADD symptoms share the same novel change in exon 11, c.1052C>T, resulting in a threonine-to-isoleucine change. The replacement is a nonconservative amino acid change that occurs in the C-terminal all-alpha domain of the MCAD protein. Here we report the finding of a novel missense mutation, c.1052C>T (p.Thr326Ile), in the ACADM gene. To our knowledge, c.1052C>T has not been previously reported in the literature or in any of the current databases we utilize. We hypothesize that this particular mutation in combination with p.Lys304Glu results in an intermediate clinical phenotype of MCADD.
PubDate: Tue, 22 Dec 2015 08:22:00 +000
- Mitchell-Riley Syndrome: A Novel Mutation in RFX6 Gene
Abstract: A novel RFX6 homozygous missense mutation was identified in an infant with Mitchell-Riley syndrome. The most common features of Mitchell-Riley syndrome were present, including severe neonatal diabetes associated with annular pancreas, intestinal malrotation, gallbladder agenesis, cholestatic disease, chronic diarrhea, and severe intrauterine growth restriction. Perijejunal tissue similar to pancreatic tissue was found in the submucosa, a finding that has not been previously reported in this syndrome. This case associating RFX6 mutation with structural and functional pancreatic abnormalities reinforces the RFX6 gene role in pancreas development and β-cell function, adding information to the existent mutation databases.
PubDate: Thu, 03 Dec 2015 14:04:34 +000
- The Use of High-Density SNP Array to Map Homozygosity in Consanguineous
Families to Efficiently Identify Candidate Genes: Application to
Abstract: Two consanguineous Qatari siblings presented for evaluation: a 17-4/12-year-old male with hypogonadotropic hypogonadism, alopecia, intellectual disability, and microcephaly and his 19-year-old sister with primary amenorrhea, alopecia, and normal cognition. Both required hormone treatment to produce secondary sex characteristics and pubertal development beyond Tanner 1. SNP array analysis of both probands was performed to detect shared regions of homozygosity which may harbor homozygous mutations in a gene causing their common features of abnormal pubertal development, alopecia, and variable cognitive delay. Our patients shared multiple homozygous genomic regions; ten shared regions were >1 Mb in length and constituted 0.99% of the genome. DCAF17, encoding a transmembrane nuclear protein of uncertain function, was the only gene identified in a homozygous region known to cause hypogonadotropic hypogonadism. DCAF17 mutations are associated with Woodhouse-Sakati syndrome, a rare disorder characterized by alopecia, hypogonadotropic hypogonadism, sensorineural hearing loss, diabetes mellitus, and extrapyramidal movements. Sequencing of the coding exons and flanking intronic regions of DCAF17 in the proband revealed homozygosity for a previously described founder mutation (c.436delC). Targeted DCAF17 sequencing of his affected sibling revealed the same homozygous mutation. This family illustrates the utility of SNP array testing in consanguineous families to efficiently and inexpensively identify regions of genomic homozygosity in which genetic candidates for recessive conditions can be identified.
PubDate: Tue, 17 Nov 2015 08:58:58 +000
- Hereditary Neuropathy with Liability to Pressure Palsies Masked by
Previous Gunshots and Tuberculosis
Abstract: Objectives. Although hereditary neuropathy with liability to pressure palsies (HNPP) presents with a distinct phenotype on history, clinical exam, and nerve conduction studies, it may be masked if diagnostic work-up suggests other causes. Case Report. In a 37-year-old male with pseudoradicular lumbar pain, neurological exam revealed sore neck muscles, peripheral facial nerve palsy, right anacusis and left hypoacusis, hemihypesthesia of the right face, mild distal quadriparesis, diffuse wasting, and generally reduced tendon reflexes. He had a history of skull fracture due to a gunshot behind the right ear and tuberculosis for which he had received adequate treatment for 3 years; MRI revealed a disc prolapse at C6/7 and Th11/12. Nerve conduction studies were indicative of demyelinating polyneuropathy with conduction blocks. Despite elevated antinuclear antibodies and elevated CSF-protein, HNPP was diagnosed genetically after having excluded vasculitis, CIDP, radiculopathy, and the side effects of antituberculous treatment. Conclusions. HNPP may manifest with mild, painless, distal quadriparesis. The diagnosis of HNPP may be blurred by a history of tuberculosis, tuberculostatic treatment, hepatitis, and the presence of elevated CSF-protein.
PubDate: Wed, 11 Nov 2015 11:22:46 +000
- Whole Exome Sequencing Reveals Compound Heterozygosity for Ethnically
Distinct PEX7 Mutations Responsible for Rhizomelic Chondrodysplasia
Punctata, Type 1
Abstract: We describe two brothers who presented at birth with bone growth abnormalities, followed by development of increasingly severe intellectual and physical disability, growth restriction, epilepsy, and cerebellar and brain stem atrophy, but normal ocular phenotypes. Case 1 died at 19 years of age due to chronic respiratory illnesses without a unifying diagnosis. The brother remains alive but severely disabled at 19 years of age. Whole exome sequencing identified compound heterozygous stop mutations in the peroxisome biogenesis factor 7 gene in both individuals. Mutations in this gene cause rhizomelic chondrodysplasia punctata, type 1 (RCDP1). One mutation, , has only been documented once before in a Japanese family, which is of interest given these two boys are of European descent. The other mutation, , is found in approximately 50% of RCDP1 patients. These are the first cases of RCDP1 that describe the coinheritance of the and mutations and demonstrate the utility of WES in cases with unclear diagnoses.
PubDate: Mon, 26 Oct 2015 11:46:37 +000