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Background: The switch/sucrose nonfermenting (SWI/SNF) complex is an adenosine triphosphate-dependent chromatin-remodeling complex associated with the regulation of DNA accessibility. Germline mutations in the components of the SWI/SNF complex are related to human developmental disorders, including the Coffin–Siris syndrome (CSS), Nicolaides–Baraitser syndrome (NCBRS), and nonsyndromic intellectual disability. These disorders are collectively referred to as SWI/SNF complex-related intellectual disability disorders (SSRIDDs). Methods: Whole-exome sequencing was performed in 564 Korean patients with neurodevelopmental disorders. Twelve patients with SSRIDDs (2.1%) were identified and their medical records were retrospectively analyzed. Results: ARID1B, found in eight patients, was the most frequently altered gene. Four patients harbored pathogenic variants in SMARCA4, SMARCB1, ARID2, and SMARCA2. Ten patients were diagnosed with CSS, and one patient without a typical phenotype was diagnosed with ARID1B-related nonsyndromic intellectual disability. Another patient harboring the SMARCA2 pathogenic variant was diagnosed with NCBRS. All pathogenic variants in ARID1B were truncating, whereas variants in SMARCA2, SMARCB1, and SMARCA4 were nontruncating (missense). Frequently observed phenotypes were thick eyebrows (10/12), hypertrichosis (8/12), coarse face (8/12), thick lips (8/12), and long eyelashes (8/12). Developmental delay was observed in all patients, and profound speech delay was also characteristic. Agenesis or hypoplasia of the corpus callosum was observed in half of the patients (6/12). Conclusions: SSRIDDs have a broad disease spectrum, including NCBRS, CSS, and ARID1B-related nonsyndromic intellectual disability. Thus, SSRIDDs should be considered as a small but important cause of human developmental disorders. [ABSTRACT FROM AUTHOR]

Background Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) has a wide phenotypic spectrum including Kallmann syndrome (KS) and normosmic idiopathic hypogonadotropic hypogonadism (nIHH). FGFR1 mutations have been identified in 3–10% of patients with KS or nIHH. This study was performed to investigate clinical phenotypes and functional characteristics of FGFR1 mutations in patients with IGD. Methods This study included 8 patients (from 7 families) with FGFR1 mutations identified by targeted gene panel sequencing or whole exome sequencing (WES). The impact of the identified mutations on FGFR1 function was assessed using in vitro studies. Results Seven heterozygous mutations in FGFR1 were identified in 8 patients from 7 independent families. The patients exhibited a wide spectrum of pubertal development, including anosmia in a prepubertal boy (n=1), delayed puberty (n=2), nIHH (n=3), and KS (n=2). Four of the mutations were classified as likely pathogenic, and the other three were variants of uncertain significance. FGF8-FGFR1 signaling activities for the novel FGFR1 variants (p.Y339H, p.S681I, and p.N185Kfs*16) were reduced by in vitro functional assay, indicating loss-of-function mutations. Conclusions This study identified seven rare sequence variants in FGFR1 in patients with KS and nIHH. Probands with an FGFR1 mutations displayed a wide phenotypic spectrum ranging from KS to anosmia. A prepubertal male with anosmia should be followed up to assess pubertal development because they can manifest hypogonadotropic hypogonadism after puberty. These results expand the phenotypic spectrum of FGFR1 mutations and suggest a broader biologic role of FGFR1 in reproduction. [ABSTRACT FROM AUTHOR]

Ornithine transcarbamylase (OTC) deficiency is an X-linked inborn error of the urea cycle that leads to the accumulation of ammonia, resulting in neurological deficits. This study was performed to describe the clinical outcomes, biochemical features and molecular spectra of patients with OTC deficiency. A total of 49 patients from 47 unrelated Korean pedigrees were included who were diagnosed with OTC deficiency based on biochemical findings and molecular analyses. Patient clinical features, biochemical findings and molecular data were analyzed retrospectively. Males with neonatal-onset phenotype presented with seizure or altered mentality (n=20). Biochemical findings showed high blood ammonia (1132.5±851.6 μmol l−1) and urine orotic acid (1840.7±1731.3 mmol mol−1 Cr) levels. There were also five males with late-onset disease who presented with vomiting, irritability and seizure at age 8.2±9.4 years old (range, 0.6-20 years). Symptomatic females presented with vomiting, seizure, and altered mentality at age 3.5±3.5 years (range, 0.2-12.8 years; n=24). More males with the late-onset form and symptomatic females displayed mild hyperammonemia and orotic aciduria compared with those showing a neonatal phenotype (P<0.05). Molecular analysis identified 37 different mutations (22 missense, 5 large deletions, 4 small deletions, 1 insertion, 3 nonsense and 2 splice sites) from all 49 patients; the mutations were dispersed throughout all coding exons. In Korean patients with OTC deficiency, mutations in OTC are genetically heterogeneous. Male patients with the neonatal-onset phenotype showed poor outcomes because of severe hyperammonemia. Early diagnosis and interventions for hyperammonemia can provide more favorable prognosis. [ABSTRACT FROM AUTHOR]

Background/Aims: This study aimed to clarify the frequency, phenotypes, and molecular spectrum of DUOX2, TPO, TSHR, and TG mutations in patients with congenital hypothyroidism (CH) with enlarged or normal-sized eutopic thyroid glands. Methods: The study cohort included 43 subjects from 41 unrelated families who had CH with eutopic thyroid glands. Mutation analyses of DUOX2, TPO, and TSHR were performed. The functional capacities of novel missense variants of DUOX2 were verified by measuring H2O2 generation in vitro. Results: Of the 43 subjects, 23 (53.5%) had sequence variants in at least one gene. Twelve different DUOX2 variants, including seven novel variants, were identified in 20 subjects. A functional analysis of the DUOX2 variants revealed that most variants, other than p.G206V and p.H678R, caused a significant reduction in H2O2 generation. Therefore, 15 subjects harbored functionally deleterious DUOX2 variants. Of these, 5 subjects had transient CH, and 10 were found to have permanent CH. Sequence variants in TSHR were identified in 5 subjects. One of the 43 subjects (2.3%) had sequence variants in two different genes. Conclusions:DUOX2 variants are a relatively common cause of CH with normal-sized or enlarged eutopic thyroid glands. Variable phenotypes were associated with partial loss of the functional activity of DUOX2 variants. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Fabry disease is a rare X-linked recessive glycosphingolipid storage disease that is caused by a deficiency of the lysosomal α-galactosidase A (GLA) enzyme, encoded by the GLA gene. This deficiency leads to the accumulation of glycosphingolipids throughout the body, which, in turn, causes multisystem diseases associated with renal, cardiovascular, and cerebrovascular complications. Recent molecular studies of GLA have demonstrated the existence of atypical variants in Fabry disease, suggesting significant genotype-phenotype correlations. In this study, we describe a renal variant of Fabry disease caused by a novel small insertion mutation in the GLA gene. [ABSTRACT FROM AUTHOR]

Disorders of sex development (DSD) vary phenotypically and are caused by a number of genetic etiologies. This study investigated the genetic etiology of DSD patients using targeted exome sequencing of 67 known DSD-associated genes in humans. This study included 37 patients with 46, XY DSD and seven patients with 46, XX DSD. We identified known pathogenic mutations or deletion in nine (20.5%) patients in the AR , CYP17A1 , SRD5A1 , and DMRT1/2 genes. Novel variants were identified in nine patients (20.5%) in the AR , ATRX, CYP17A1, CHD7 , MAP3K1 , NR5A1 , and WWOX genes. Among them, four patients harbored pathogenic or likely pathogenic variants, while the remaining five patients (11.4%) had variants of uncertain significance. We were able to make a genetic diagnosis in 29.5% of patients with pathogenic or likely pathogenic mutations. Targeted exome sequencing is an efficient tool to improve the diagnostic yield of DSD, despite its phenotypic and genetic heterogeneity. [ABSTRACT FROM AUTHOR]

Highlights: [•] Menkes disease-derived induced pluripotent stem cells (MD-iPSCs) showed aberrant cadherin switch during in vitro differentiation. [•] MD-iPSCs showed impaired neural rosette formation during in vitro differentiation. [•] Copper chelation reproduced similar phenotypes shown in MD-iPSCs. [ABSTRACT FROM AUTHOR]

Purpose: To describe clinical and molecular characteristics of Korean patients with aniridia and to compare the clinical phenotype between those having an identifiable PAX6 mutation and those not. Design: Comparative case series. Participants: A total of 14 Korean patients from 10 families with aniridia. Methods: Complete ophthalmologic examinations were performed for all patients. PAX6 analysis included direct sequencing of all coding regions and multiplex ligation-dependent probe amplification (MLPA) to detect large deletions when the sequencing was negative. If the PAX6 analysis failed to reveal any identifiable mutations, genomic copy number variation analysis via array comparative genomic hybridization (CGH) and candidate gene PITX3 and FOXE3 sequencing were then performed. Main Outcome Measures: Severity of ocular abnormalities and genetic findings. Results: Sequencing of PAX6 exhibited 5 different heterozygous mutations in 8 patients from 5 families; 2 (p.Ser43Phe, IVS8-9C>G) were novel, and 3 (p.Arg208Trp, p.Arg317X, and p.X423L) have been previously reported. Among the remaining 6 patients in whom the PAX6 sequencing was negative, MLPA identified large deletions in 2 sporadic patients. However, the array CGH and candidate gene sequencing found no genomic or genetic abnormalities. The mutation detection rate was therefore 70%. Patients harboring an identifiable mutation in PAX6 had either a severe or a mild variant phenotype depending on the type of mutations. Likewise, among patients without an identifiable PAX6 mutation, their phenotypes varied widely from severe to very mild. Conclusions: This study adds 2 novel PAX6 mutations to those previously reported, providing further evidence for genetic and phenotypic heterogeneity in aniridic ocular malformation. There was no difference in the clinical phenotype between patients with and without detectable mutations in the PAX6 gene. The wide variability of ocular phenotype regardless of the presence or absence of PAX6 mutations calls for a further appreciation of the complexity in the molecular diagnosis of aniridia and suggests that this ocular malformation may be better regarded as a group of heterogeneous disorders, rather than a single disease entity, associated with mutations in PAX6 and/or other genes located elsewhere in the human genome. Financial Disclosure(s): The authors have no proprietary or commercial interest in any of the materials discussed in this article. [Copyright &y& Elsevier]

Abstract: Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is a common autosomal recessive disorder. Ornithine transcarbamylase (OTC) deficiency is the most common urea cycle disorder and demonstrates X-linked inheritance. In female OTC deficiency, phenotypes are variable according to X-inactivation patterns. These disorders develop separately, and their co-morbidity is extremely rare. We report one girl with CAH showing recurrent hyperammonemia and hepatitis after 2years-of-age due to additional OTC deficiency. [Copyright &y& Elsevier]