Whole-exome sequencing analysis of Waardenburg syndrome in a Chinese family.
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ABSTRACT:
SUBMITTER: Chen D
PROVIDER: S-EPMC5489998 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:OBJECTIVE: Nance-Horan syndrome (NHS) is a rare X-linked disorder characterized by congenital nuclear cataracts, dental anomalies, and craniofacial dysmorphisms. Mental retardation was present in about 30% of the reported cases. The purpose of this study was to investigate the genetic and clinical features of NHS in a Chinese family. METHODS: Whole exome sequencing analysis was performed on DNA from an affected male to scan for candidate mutations on the X-chromosome. Sanger sequencing was used to verify these candidate mutations in the whole family. Clinical and ophthalmological examinations were performed on all members of the family. RESULTS: A combination of exome sequencing and Sanger sequencing revealed a nonsense mutation c.322G>T (E108X) in exon 1 of NHS gene, co-segregating with the disease in the family. The nonsense mutation led to the conversion of glutamic acid to a stop codon (E108X), resulting in truncation of the NHS protein. Multiple sequence alignments showed that codon 108, where the mutation (c.322G>T) occurred, was located within a phylogenetically conserved region. The clinical features in all affected males and female carriers are described in detail. CONCLUSIONS: We report a nonsense mutation c.322G>T (E108X) in a Chinese family with NHS. Our findings broaden the spectrum of NHS mutations and provide molecular insight into future NHS clinical genetic diagnosis.
| S-EPMC4129093 | biostudies-literature
Project description:BACKGROUND AND OBJECTIVES:Steroid-resistant nephrotic syndrome overwhelmingly progresses to ESRD. More than 30 monogenic genes have been identified to cause steroid-resistant nephrotic syndrome. We previously detected causative mutations using targeted panel sequencing in 30% of patients with steroid-resistant nephrotic syndrome. Panel sequencing has a number of limitations when compared with whole exome sequencing. We employed whole exome sequencing to detect monogenic causes of steroid-resistant nephrotic syndrome in an international cohort of 300 families. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS:Three hundred thirty-five individuals with steroid-resistant nephrotic syndrome from 300 families were recruited from April of 1998 to June of 2016. Age of onset was restricted to <25 years of age. Exome data were evaluated for 33 known monogenic steroid-resistant nephrotic syndrome genes. RESULTS:In 74 of 300 families (25%), we identified a causative mutation in one of 20 genes known to cause steroid-resistant nephrotic syndrome. In 11 families (3.7%), we detected a mutation in a gene that causes a phenocopy of steroid-resistant nephrotic syndrome. This is consistent with our previously published identification of mutations using a panel approach. We detected a causative mutation in a known steroid-resistant nephrotic syndrome gene in 38% of consanguineous families and in 13% of nonconsanguineous families, and 48% of children with congenital nephrotic syndrome. A total of 68 different mutations were detected in 20 of 33 steroid-resistant nephrotic syndrome genes. Fifteen of these mutations were novel. NPHS1, PLCE1, NPHS2, and SMARCAL1 were the most common genes in which we detected a mutation. In another 28% of families, we detected mutations in one or more candidate genes for steroid-resistant nephrotic syndrome. CONCLUSIONS:Whole exome sequencing is a sensitive approach toward diagnosis of monogenic causes of steroid-resistant nephrotic syndrome. A molecular genetic diagnosis of steroid-resistant nephrotic syndrome may have important consequences for the management of treatment and kidney transplantation in steroid-resistant nephrotic syndrome.
| S-EPMC5753307 | biostudies-other
Project description:BackgroundRoberts syndrome (RBS) is a rare autosomal recessive disorder caused by variations in the ESCO2 gene; however, prenatal diagnosis of RBS has never been reported in Chinese families. Additionally, fetal-specific phenotypic characteristics associated with ESCO2 variants have not been reported.Case presentationA fetus in a healthy, nonconsanguineous Chinese family with multiple serious congenital malformations was diagnosed prenatally. Two consecutive fetuses in this family presented with tetraphocomelia, growth restriction, cleft lip and palate bilaterally, and other abnormalities. The main phenotypic characteristics of this case were strongly suspected to be associated with RBS. Finally, whole exome sequence analysis revealed the insertion of a homozygous base pair in exon 6 of the ESCO2 gene (NM_001017420.3, c.1111insA, NP_001017420.1, p.Thr371fs). Both of the couples were heterozygous carriers for this variant.ConclusionWe are the first to report a prenatal case of RBS diagnosed in a Chinese family. Here, we have confirmed that the rare variant is a definite pathogenic variant, and we provide detailed phenotypic characteristics for the prenatal diagnosis of RBS due to this causative variant.
| S-EPMC8800352 | biostudies-literature
Project description:BACKGROUND:Joubert syndrome (JS, OMIM: 213300) is a recessive developmental disorder characterized by cerebellar vermis hypoplasia and a distinctive mid-hindbrain malformation called the "molar tooth sign" on axial magnetic resonance imaging. To date, more than 35 ciliary genes have been identified as the causative genes of JS. METHODS:Whole exome sequencing was performed to detect the causative gene mutations in a Chinese patient with JS followed by Sanger sequencing. RT-PCR and Sanger sequencing were used to confirm the abnormal transcript of centrosomal protein 104 (CEP104, OMIM: 616690). RESULTS:We identified two novel heterozygous mutations of CEP104 in the proband, which were c.2364+1G>A and c.414delC (p.Asn138Lysfs*11) (GenBank: NM_014704.3) and consistent with the autosomal recessive inheritance mode. CONCLUSION:Our study reported the fourth case of JS patients with CEP104 mutations, which expands the mutation spectrum of CEP104 and elucidates the clinical heterogeneity of JS.
| S-EPMC6900356 | biostudies-literature
Project description:In the present study we attempted a parent-child trio, whole exome sequencing (WES) approach to study Apert's syndrome. Clinical characteristics of the child were noted down and WES was carried out using Ion Torrent System that revealed the presence of previously reported P253R mutation in FGFR2 gene. Presence of two SNPs rs1047057 and rs554851880 in FGFR2 gene with an allelic frequency of 0.5113 and 0.001176 respectively and 161 complete damaging mutations were found. This study is the first reported case of exome sequencing approach on an Apert's syndrome patient aimed at providing better genetic counselling in a non-consanguineous relationship.
| S-EPMC6147108 | biostudies-literature
Project description:Familial chylomicronemia syndrome (FCS) is a rare monogenic autosomal recessive disease caused by loss-of-function mutations in genes involved in chylomicron breakdown through hydrolysis of triglycerides into free fatty acids. Patients are often diagnosed in early childhood with extremely high triglyceride levels and symptoms including abdominal pain, eruptive cutaneous xanthomata, hepatosplenomegaly, and significant cognitive, psychological, and social impairment. The most serious medical condition suffered by FCS patients is recurrent acute pancreatitis. Lipoprotein lipase (LPL) gene mutation accounts for majority of the known pathogenic mutations. Early diagnosis and strict low-fat diet are critical for successful management of the triglyceride concentration to lower the risk of pancreatitis. The true prevalence of FCS in China is unknown and here we report a Chinese female preterm neonate presented with an extremely high triglyceride level of 22.11 mmol/L on day 13 after birth. Clinical and laboratory workup including whole-exome sequencing revealed two novel compound heterozygous LPL mutations (c.406G > C and c.829G > C) that are co-segregated with her non-consanguineous parents, consistent with autosomal recessive inheritance. A diagnosis of FCS based on clinical, biochemical, and genetic ground was made to guide her management.
| S-EPMC7379882 | biostudies-literature
Project description:Paramyotonia congenita (PC) is a rare autosomal dominant neuromuscular disorder characterized by juvenile onset and development of cold-induced myotonia after repeated activities. The disease is mostly caused by genetic mutations of the sodium channel, voltage-gated, type IV, alpha subunit (SCN4A) gene. This study intended to systematically identify the causative genetic variations of a Chinese Han PC family. Seven members of this PC family, including four patients and three healthy controls, were selected for whole exome sequencing (WES) using the Illumina HiSeq platform. Sequence variations were identified using the SoftGenetics program. The mutation R1448C of SCN4A was found to be the only causative mutation. This study applied WES technology to sequence multiple members of a large PC family and was the first to systematically confirm that the genetic change in SCN4A is the only causative variation in this PC family and the SCN4A mutation is sufficient to lead to PC.
| S-EPMC4535863 | biostudies-literature
Project description:BACKGROUND:Variants in the emerin gene (EMD) were implicated in X-linked recessive Emery-Dreifuss muscular dystrophy (EDMD), characterized by early-onset contractures of tendons, progressive muscular weakness and cardiomyopathy. To date, 223 mutations have been reported in EMD gene and the majority of them caused a predominant skeletal muscular phenotype. In this study, we identified a novel deletion mutation in EMD exon 1, which results in almost a complete loss of emerin protein in a large Chinese family. However, the patients suffered severe dilated cardiomyopathy (DCM) but very mild skeletal muscle disorder. CASE PRESENTATION:Whole exome sequencing (WES) and linkage analysis were performed to identify the underlying mutation in a Chinese DCM family spanning five generations. A missense variation in the GPR50 gene was found co-segregated with the disease phenotype, whereas no functional alteration was detected in the variant GPR50 protein. When analyzing the failure sequences in the exome sequencing data, a novel deletion mutation (c.26_39delATACCGAGCTGACC) in EMD exon 1, was identified in this family. Different from the typical clinical features caused by most reported EMD mutations, patients in our study presented very mild skeletal muscle degeneration that had not been diagnosed until the mutation was found. CONCLUSION:We described a family with rare clinical presentations caused by a novel EMD deletion mutation. Our findings broaden the heterogeneous spectrum of phenotypes attributed to EMD mutations and provide new insight to explain the genotype-phenotype correlations between EMD mutations and EDMD symptoms.
| S-EPMC4105140 | biostudies-literature
Project description:PURPOSE:Macrozoospermia is a rare sperm morphologic abnormality associated with male infertility and is characterized by a high percentage of spermatozoa with large irregular heads. The aim of this study was to identify the genetic cause of an infertile male with macrozoospermia from a consanguineous family. METHODS:Whole-exome sequencing (WES) was performed using peripheral blood genomic DNA from the patient and his parents. RESULTS:WES analysis of the patient with macrozoospermia from a consanguineous family allowed the identification of a novel homozygous missense variant in the AURKC gene (c.269G>A). Bioinformatics analysis also suggested this variant a pathogenic mutation. Quantitative real-time PCR analysis showed that the mRNA level of AURKC is significantly decreased in the patient compared with his father. Moreover, no embryos were available for transfer after ICSI. CONCLUSIONS:These results further support the important role of AURKC in male infertility and guide the practitioner in optimal decision making for patients with macrozoospermia.
| S-EPMC6439091 | biostudies-literature
Project description:INTRODUCTION:Gout is a worldwide chronic disease generally caused by high serum levels of uric acid. Using whole exome sequencing, we aimed to explore genetic alterations in hereditary gout. PATIENTS' CONCERNS:There were 9 direct descendants diagnosed with gout in total in this family. The patients concerned about the high incidence and inheritance of gout. DIAGNOSIS:The youngest propositus was diagnosed as gout in our hospital. Diagnoses of other patients in this family were made on the foundation of history and clinical tests. INTERVENTIONS:Six direct descendants and 3 healthy spouses in 1 family were recruited in our study. Whole-exome sequencing was conducted in all participants. OUTCOMES:Whole-exome sequencing and genetic analysis revealed 2 putative rare inherited deleterious variants, which were detected only in direct descendants. Twelve gout and uric acid (UC)-related nucleotide sequence variants previously reported by GWAS were detected among all subjects. CONCLUSIONS:In the case of this family, the GWAS identified gout and UC-related nucleotide sequence variants may increase the risk of developing gout, but penetrance was not complete. The rare sequence variants in low-density lipoprotein receptor-related protein 1 (LRP1) and oncoprotein induced transcript 3 (OIT3) may have contributed to inheritance of gout within the 5 generations of family members in this study.
| S-EPMC7310917 | biostudies-literature