scholarly journals Association of a novel missense mutation in MYO15A with nonsyndromic hearing loss: a case report

2020 ◽  
Author(s):  
Siji Wang ◽  
Ziqi Chen ◽  
Jiaqiu Dai ◽  
Xi Ouyang ◽  
Lin Zhu ◽  
...  

Abstract Background Hearing loss is a common disease globally, and more than 50% of the cases are genetic. Autosomal recessive nonsyndromic hearing loss (ARNSHL) is one of the most common types of hereditary hearing loss. Here, a novel MYO15A missense mutation was identified in a Chinese family with ARNSHL, using targeted genetic sequencing and Sanger sequencing. Case presentation: A 6-year-old girl with congenital nonsyndromic sensorineural deafness was presented from the First Affiliated hospital of Chongqing Medical University, China. We used targeted region sequencing, Sanger sequencing, functional prediction, and three-dimensional protein structure modeling to identify and verify the genes responsible for deafness in the family. Conclusions We found pathogenic compound heterozygous mutations in MYO15A, including a novel missense mutation, c.6353T > C (p.Leu2118Pro). It could provide help not only for genetic counseling but also for further understanding of the functional role of MYO15A mutations.

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1474
Author(s):  
Khushnooda Ramzan ◽  
Nouf S. Al-Numair ◽  
Sarah Al-Ageel ◽  
Lina Elbaik ◽  
Nadia Sakati ◽  
...  

Mutant alleles of CDH23, a gene that encodes a putative calcium-dependent cell-adhesion glycoprotein with multiple cadherin-like domains, are responsible for both recessive DFNB12 nonsyndromic hearing loss (NSHL) and Usher syndrome 1D (USH1D). The encoded protein cadherin 23 (CDH23) plays a vital role in maintaining normal cochlear and retinal function. The present study’s objective was to elucidate the role of DFNB12 allelic variants of CDH23 in Saudi Arabian patients. Four affected offspring of a consanguineous family with autosomal recessive moderate to profound NSHL without any vestibular or retinal dysfunction were investigated for molecular exploration of genes implicated in hearing impairment. Parallel to this study, we illustrate some possible pitfalls that resulted from unexpected allelic heterogeneity during homozygosity mapping due to identifying a shared homozygous region unrelated to the disease locus. Compound heterozygous missense variants (p.(Asp918Asn); p.(Val1670Asp)) in CDH23 were identified in affected patients by exome sequencing. Both the identified missense variants resulted in a substitution of the conserved residues and evaluation by multiple in silico tools predicted their pathogenicity and variable disruption of CDH23 domains. Three-dimensional structure analysis of human CDH23 confirmed that the residue Asp918 is located at a highly conserved DXD peptide motif and is directly involved in “Ca2+” ion contact. In conclusion, our study identifies pathogenic CDH23 variants responsible for isolated moderate to profound NSHL in Saudi patients and further highlights the associated phenotypic variability with a genotypic hierarchy of CDH23 mutations. The current investigation also supports the application of molecular testing in the clinical diagnosis and genetic counseling of hearing loss.


Medicina ◽  
2018 ◽  
Vol 54 (2) ◽  
pp. 28
Author(s):  
Pavlina Plevova ◽  
Petra Tvrda ◽  
Martina Paprskarova ◽  
Petra Turska ◽  
Barbara Kantorova ◽  
...  

Background and Objective: Hearing loss is the most common sensory deficit in humans. The aim of this study was to clarify the genetic aetiology of nonsyndromic hearing loss in the Moravian-Silesian population of the Czech Republic. Patients and Methods: This study included 200 patients (93 males, 107 females, mean age 16.9 years, ranging from 4 months to 62 years) with nonsyndromic sensorineural hearing loss. We screened all patients for mutations in GJB2 and the large deletion del(GJB6-D13S1830). We performed further screening for additional genes (SERPINB6, TMIE, COCH, ESPN, ACTG1, KCNQ4, and GJB3) with Sanger sequencing on a subset of patients that were negative for GJB2 mutations. Results: We detected biallelic GJB2 mutations in 44 patients (22%). Among these patients, 63.6%, 9.1% and 2.3% exhibited homozygous c.35delG, p.Trp24*, and p.Met34Thr mutations, respectively. The remaining 25% of these patients exhibited compound heterozygous c.35delG, c.-23+1G>A, p.Trp24*, p.Val37Ile, p.Met34Thr, p.Leu90Pro, c.235delC, c.313_326del14, p.Ser139Asn, and p.Gly147Leu mutations. We found a monoallelic GJB2 mutation in 12 patients (6.6%). We found no pathogenic mutations in the other tested genes. Conclusions: One fifth of our cohort had deafness related to GJB2 mutations. The del(GJB6-D13S1830), SERPINB6, TMIE, COCH, ESPN, ACTG1, GJB3, and KCNQ4 mutations were infrequently associated with deafness in the Moravian-Silesian population. Therefore, we suggest that del(GJB6-D13S1830) testing should be performed only when patients with deafness carry the monoallelic GJB2 mutation.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Guangxian Yang ◽  
Yi Yin ◽  
Zhiping Tan ◽  
Jian Liu ◽  
Xicheng Deng ◽  
...  

Abstract Background Previous studies have revealed that mutations of Spalt Like Transcription Factor 1 (SALL1) are responsible for Townes-Brocks syndrome (TBS), a rare genetic disorder that is characterized by an imperforate anus, dysplastic ears, thumb malformations and other abnormalities, such as hearing loss, foot malformations, renal impairment with or without renal malformations, genitourinary malformations, and congenital heart disease. In addition, the protein tyrosine phosphatase receptor type Q (PTPRQ) gene has been identified in nonsyndromic hearing loss patients with autosomal recessive or autosomal dominant inherited patterns. Methods A Chinese family with TBS and hearing loss was enrolled in this study. The proband was a two-month-old girl who suffered from congenital anal atresia with rectal perineal fistula, ventricular septal defect, patent ductus arteriosus, pulmonary hypertension (PH), and finger deformities. The proband’s father also had external ear deformity with deafness, toe deformities and PH, although his anus was normal. Further investigation found that the proband’s mother presented nonsyndromic hearing loss, and the proband’s mother’s parents were consanguine married. Whole-exome sequencing and Sanger sequencing were applied to detect the genetic lesions of TBS and nonsyndromic hearing loss. Results Via whole-exome sequencing and Sanger sequencing of the proband and her mother, we identified a novel heterozygous mutation (ENST00000251020: c.1428_1429insT, p. K478QfsX38) of SALL1 in the proband and her father who presented TBS phenotypes, and we also detected a new homozygous mutation [ENST00000266688: c.1057_1057delC, p. L353SfsX8)] of PTPRQ in the proband’s mother and uncle, who suffered from nonsyndromic hearing loss. Both mutations were located in the conserved sites of the respective protein and were predicted to be deleterious by informatics analysis. Conclusions This study confirmed the diagnosis of TBS at the molecular level and expanded the spectrum of SALL1 mutations and PTPRQ mutations. Our study may contribute to the clinical management and genetic counselling of TBS and hearing loss.


2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Xiaohong Meng ◽  
Qiyou Li ◽  
Hong Guo ◽  
Haiwei Xu ◽  
Shiying Li ◽  
...  

Purpose. To characterize the clinical and molecular genetic characteristics of a large, multigenerational Chinese family showing different phenotypes. Methods. A pedigree consisted of 56 individuals in 5 generations was recruited. Comprehensive ophthalmic examinations were performed in 16 family members affected. Mutation screening of CYP4V2 was performed by Sanger sequencing. Next-generation sequencing (NGS) was performed to capture and sequence all exons of 47 known retinal dystrophy-associated genes in two affected family members who had no mutations in CYP4V2. The detected variants in NGS were validated by Sanger sequencing in the family members. Results. Two compound heterozygous CYP4V2 mutations (c.802-8_810del17insGC and c.992A>C) were detected in the proband who presented typical clinical features of BCD. One missense mutation (c.1482C>T, p.T494M) in the PRPF3 gene was detected in 9 out of 22 affected family members who manifested classical clinical features of RP. Conclusions. Our results showed that two compound heterozygous CYP4V2 mutations caused BCD, and one missense mutation in PRPF3 was responsible for adRP in this large family. This study suggests that accurate phenotypic diagnosis, molecular diagnosis, and genetic counseling are necessary for patients with hereditary retinal degeneration in some large mutigenerational family.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Xue Gao ◽  
Jin-Cao Xu ◽  
Wei-Qian Wang ◽  
Yong-Yi Yuan ◽  
Dan Bai ◽  
...  

Hereditary nonsyndromic hearing loss is extremely heterogeneous. Mutations in the POU class 4 transcription factor 3 (POU4F3) are known to cause autosomal dominant nonsyndromic hearing loss linked to the loci of DFNA15. In this study, we describe a pathogenic missense mutation in POU4F3 in a four-generation Chinese family (6126) with midfrequency, progressive, and postlingual autosomal dominant nonsyndromic hearing loss (ADNSHL). By combining targeted capture of 129 known deafness genes, next-generation sequencing, and bioinformatic analysis, we identified POU4F3 c.602T>C (p.Leu201Pro) as the disease-causing variant. This variant cosegregated with hearing loss in other family members but was not detected in 580 normal controls or the ExAC database and could be classified as a “pathogenic variant” according to the American College of Medical Genetics and Genomics guidelines. We conclude that POU4F3 c.602T>C (p.Leu201Pro) is related to midfrequency hearing loss in this family. Routine examination of POU4F3 is necessary for the genetic diagnosis of midfrequency hearing loss.


2021 ◽  
Author(s):  
Yang Guangxian ◽  
Yin Yi ◽  
Tan Zhiping ◽  
Liu Jian ◽  
Deng Xicheng ◽  
...  

Abstract Background: Previous studies have revealed that mutations of Spalt Like Transcription Factor 1 (SALL1) are responsible for Townes-Brocks syndrome (TBS), a rare genetic disorder that is characterized by an imperforate anus, dysplastic ears, thumb malformations and other abnormalities, such as hearing loss, foot malformations, renal impairment with or without renal malformations, genitourinary malformations, and congenital heart disease (CHD). In addition, the protein tyrosine phosphatase receptor type Q (PTPRQ) gene has been identified in nonsyndromic hearing loss patients with autosomal recessive or autosomal dominant inherited patterns.Methods: A Chinese family with TBS and hearing loss was enrolled in this study. The proband was a two-month-old girl who suffered from congenital anal atresia with rectal perineal fistula, ventricular septal defect, patent ductus arteriosus, pulmonary hypertension (PH), and finger deformities. The proband’s father also had external ear deformity with deafness, toe deformities and PH, although his anus was normal. Further investigation found that the proband’s mother presented nonsyndromic hearing loss, and the proband’s mother’s parents were consanguine married. Whole-exome sequencing and Sanger sequencing were applied to detect the genetic lesions of TBS and nonsyndromic hearing loss.Results: Via whole-exome sequencing and Sanger sequencing of the proband and her mother, we identified a novel heterozygous mutation (ENST00000251020: c.1428_1429insT, p. K478QfsX38) of SALL1 in the proband and her father who presented TBS phenotypes, and we also detected a new homozygous mutation (ENST00000266688: c.1057_1057delC, p. L353SfsX8)) of PTPRQ in the proband’s mother and uncle, who suffered from nonsyndromic hearing loss. Both mutations were located in the conserved sites of the respective protein and were predicted to be deleterious by informatics analysis.Conclusions: This study confirmed the diagnosis of TBS at the molecular level and expanded the spectrum of SALL1 mutations and PTPRQ mutations. Our study may contribute to the clinical management and genetic counselling of TBS and hearing loss.


PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0124757 ◽  
Author(s):  
Xue Gao ◽  
Yu Su ◽  
Yu-Lan Chen ◽  
Ming-Yu Han ◽  
Yong-Yi Yuan ◽  
...  

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaona Luo ◽  
Chunmei Wang ◽  
Longlong Lin ◽  
Fang Yuan ◽  
Simei Wang ◽  
...  

The gene encoding collagen like tail subunit of asymmetric acetylcholinesterase (COLQ) is responsible for the transcription of three strands of collagen of acetylcholinesterase, which is attached to the endplate of neuromuscular junctions. Mutations in the COLQ gene are inherited in an autosomal-recessive manner and can lead to type V congenital myasthenia syndrome (CMS), which manifests as decreased muscle strength at birth or shortly after birth, respiratory failure, restricted eye movements, drooping of eyelids, and difficulty swallowing. Here we reported three variants within COLQ in two unrelated children with CMS. An intronic variant (c.393+1G>A) and a novel missense variant (p.Q381P) were identified as compound heterozygous in a 13-month-old boy, with the parents being carriers of each. An intragenic deletion including exons 14 and 15 was found in a homozygous state in a 12-year-old boy. We studied the relative expression of the COLQ and AChE gene in the probands' families, performed three-dimensional protein structural analysis, and analyzed the conservation of the missense mutation c.1142A>C (p.Q381P). The splicing mutation c.393+1G>A was found to affect the normal splicing of COLQ exon 5, resulting in a 27-bp deletion. The missense mutation c.1142A>C (p.Q381P) was located in a conserved position in different species. We found that homozygous deletion of COLQ exons 14–15 resulted in a 241-bp deletion, which decreased the number of amino acids and caused a frameshift translation. COLQ expression was significantly lower in the probands than in the probands' parents and siblings, while AChE expression was significantly higher. Moreover, the mutations were found to cause significant differences in the predicted three-dimensional structure of the protein. The splicing mutation c.393+1G>A, missense mutation c.1A>C (p.Q381P), and COLQ exon 14–15 deletion could cause CMS.


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