scholarly journals Targeted Next-Generation Sequencing Identified Compound Heterozygous Mutations in MYO15A as the Probable Cause of Nonsyndromic Deafness in a Chinese Han Family

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Longhao Wang ◽  
Lin Zhao ◽  
Hu Peng ◽  
Jun Xu ◽  
Yun Lin ◽  
...  

Hearing loss is a highly heterogeneous disorder, with more than 60% of congenital cases caused by genetic factors. This study is aimed at identifying the genetic cause of congenital hearing loss in a Chinese Han family. Auditory evaluation before and after cochlear implantation and targeted next-generation sequencing of 140 deafness-related genes were performed for the deaf proband. Compound heterozygous mutations c.3658_3662del (p. E1221Wfs∗23) and c.6177+1G>T were identified in MYO15A as the only candidate pathogenic mutations cosegregated with the hearing loss in this family. These two variants were absent in 200 normal-hearing Chinese Hans and were classified as likely pathogenic and pathogenic, respectively, based on the ACMG guideline. Our study further expanded the mutation spectrum of MYO15A as the c.3658_3662del mutation is novel and confirmed that deaf patients with recessive MYO15A mutations have a good outcome for cochlear implantation.

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Pengcheng Xu ◽  
Jun Xu ◽  
Hu Peng ◽  
Tao Yang

Genetic hearing loss is a common sensory disorder, and its cause is highly heterogeneous. In this study, by targeted next-generation sequencing of 414 known deafness genes, we identified compound heterozygous mutations p.R34X/p.M413T in TMC1 and p.S3417del/p.R1407T in MYO15A in two recessive Chinese Han deaf families. Intrafamilial cosegregation of the mutations with the hearing phenotype was confirmed in both families by the Sanger sequencing. Auditory features of the affected individuals are consistent with that previously reported for recessive mutations in TMC1 and MYO15A. The two novel mutations identified in this study, p.M413T in TMC1 and p.R1407T in MYO15A, are classified as likely pathogenic according to the guidelines of ACMG. Our study expanded the mutation spectrums of TMC1 and MYO15A and illustrated that genotype-phenotype correlation in combination with next-generation sequencing may improve the accuracy for genetic diagnosis of deafness.


2019 ◽  
Author(s):  
Di Wu ◽  
Weiyuan Huang ◽  
Shuo Li ◽  
Jie Zhang ◽  
Xiaohua Chen ◽  
...  

Abstract BACKGROUND: Non-syndromic hearing loss is clinically and genetically heterogeneous. In this study, we characterized the clinical features of twelve Chinese Han deaf families in which mutations in common deafness genes GJB2 , SLC26A4 and MT-RNR1 were excluded. RESULTS: Targeted next-generation sequencing of 147 known deafness genes was performed in probands of ten families, while whole-exome sequencing was applied in those of the rest two. Pathogenic mutations in a total of 11 rare deafness genes, OTOF , CDH23 , PCDH15 , PDZD7 , ADGRV1 , KARS , OTOG , GRXCR2 , MYO6 , GRHL2 , and POU3F4 , were identified in all 12 probands, with 17 mutations being novel. Intrafamilial co-segregation of the mutations and the deafness phenotype were confirmed by Sanger sequencing. CONCLUSIONS: Our results expanded the mutation spectrum and genotype-phenotype correlation of non-syndromic hearing loss in Chinese Hans and also emphasized the importance of combining both next-generation sequencing and detailed auditory evaluation to achieve a more accurate diagnosis for non-syndromic hearing loss.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xiaoyu Yu ◽  
Yun Lin ◽  
Hao Wu

Hearing loss is the most common sensory deficit in humans. Identifying the genetic cause and genotype-phenotype correlation of hearing loss is sometimes challenging due to extensive clinical and genetic heterogeneity. In this study, we applied targeted next-generation sequencing (NGS) to resolve the genetic etiology of hearing loss in a Chinese Han family with multiple affected family members. Targeted sequencing of 415 deafness-related genes identified the heterozygous c.481C>T (p.R161C) mutation in SOX10 and the homozygous c.235delC (p.L79Cfs∗3) mutation in GJB2 as separate pathogenic mutations in distinct affected family members. The SOX10 c.481C>T (p.R161C) mutation has been previously reported in a Caucasian patient with Kallmann syndrome that features congenital hypogonadotropic hypogonadism with anosmia. In contrast, family members carrying the same p.R161C mutation in this study had variable Waardenburg syndrome-associated phenotypes (hearing loss and/or hair hypopigmentation) without olfactory or reproductive anomalies. Our results highlight the importance of applying comprehensive diagnostic approaches such as NGS in molecular diagnosis of hearing loss and show that the p.R161C mutation in SOX10 may be associated with a wide range of variable clinical manifestations.


Endocrine ◽  
2020 ◽  
Vol 70 (3) ◽  
pp. 607-615
Author(s):  
Peng Fan ◽  
Yi-Ting Lu ◽  
Kun-Qi Yang ◽  
Di Zhang ◽  
Xue-Ying Liu ◽  
...  

Abstract Purpose Apparent mineralocorticoid excess (AME) is an ultrarare autosomal recessive disorder resulting from deficiency of 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2) caused by mutations in HSD11B2. The purpose of this study was to identify novel compound heterozygous HSD11B2 mutations in a Chinese pedigree with AME and conduct a systematic review evaluating the AME clinical features associated with HSD11B2 mutations. Methods Next-generation sequencing was performed in the proband, and Sanger sequencing was used to identify candidate variants in family members, 100 hypertensives, and 100 healthy controls. A predicted structure of 11βHSD2 was constructed by in silico modeling. A systematic review was used to identify cases of HSD11B2-related AME. Data for genotyping and clinical characterizations and complications were extracted. Results Next-generation sequencing showed novel compound heterozygous mutations (c.343_348del and c.1099_1101del) in the proband with early-onset hypertension and hypokalemia. Sanger sequencing verified the monoallelic form of the same mutations in five other relatives but not in 100 hypertensives or 100 healthy subjects. In silico structural modeling showed that compound mutations may simultaneously perturb the substrate and coenzyme binding pocket. A systematic review of 101 AME patients with 54 HSD11B2 mutations revealed early-onset hypertension, hypokalemia and homozygous mutations as common features. The homozygous HSD11B2 mutations correlated with low birth weight (r = 0.285, P = 0.02). Conclusions We report novel compound heterozygous HSD11B2 mutations in a Chinese teenager with early-onset hypertension, and enriched genotypic and phenotypic spectrums in AME. Genetic testing helps early diagnosis and treatment for AME patients, which may avoid target organ damage.


2021 ◽  
Vol 11 ◽  
Author(s):  
Athanasia Stoupa ◽  
Ghada Al Hage Chehade ◽  
Rim Chaabane ◽  
Dulanjalee Kariyawasam ◽  
Gabor Szinnai ◽  
...  

ObjectiveTo elucidate the molecular cause in a well-characterized cohort of patients with Congenital Hypothyroidism (CH) and Dyshormonogenesis (DH) by using targeted next-generation sequencing (TNGS).Study designWe studied 19 well-characterized patients diagnosed with CH and DH by targeted NGS including genes involved in thyroid hormone production. The pathogenicity of novel mutations was assessed based on in silico prediction tool results, functional studies when possible, variant location in important protein domains, and a review of the recent literature.ResultsTNGS with variant prioritization and detailed assessment identified likely disease-causing mutations in 10 patients (53%). Monogenic defects most often involved TG, followed by DUOXA2, DUOX2, and NIS and were usually homozygous or compound heterozygous. Our review shows the importance of the detailed phenotypic description of patients and accurate analysis of variants to provide a molecular diagnosis.ConclusionsIn a clinically well-characterized cohort, TNGS had a diagnostic yield of 53%, in accordance with previous studies using a similar strategy. TG mutations were the most common genetic defect. TNGS identified gene mutations causing DH, thereby providing a rapid and cost-effective genetic diagnosis in patients with CH due to DH.


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