Analysis of MYO7A gene mutation in a family with non-syndromic autosomal recessive deafness / 中华医学遗传学杂志

Objective@#To explore the genetic basis for a family with non-syndromic autosomal recessive deafness.@*Methods@#The proband and her parents were subjected to physical and audiological examinations. With genomic DNA extracted from peripheral blood samples, next-generation sequencing was carried out using a panel for deafness genes. Suspected mutation was validated by Sanger sequencing and qPCR analysis of her parents.@*Results@#The proband presented bilateral severe sensorineural hearing loss at three days after birth. Her auditory threshold was 110-120 dBnHL but with absence of vestibular and retinal symptoms. Her brother also had deafness but her parents were normal. No abnormality was found upon physical examination of her family members, while audiological examination showed no middle ear or retrocochlear diseases. Next-generation sequencing identified compound heterozygous mutations of the MYO7A gene, including a previously known c. 462C>A (p. Cys154Ter) and a novel EX43_46 Del, which were respectively derived from her mother and father.@*Conclusion@#The compound heterozygous mutations of the MYO7A gene probably underlie the disease in this family. Our findings has enriched the mutation spectrum for non-syndromic autosomal recessive deafness 2.

Analysis of deafness-related gene mutations in 88 non-syndromic hearing loss patients in Fuzhou city / 中国耳鼻咽喉头颈外科

OBJECTIVE To investigate the deafness-related gene mutation frequency and hotspots in patients of Fuzhou city with non-syndromic hearing loss (NSHL). METHODS Peripheral blood samples were obtained from 88 cases of patients with hearing loss after clinical history inquiry and clinical examination. Their genomic DNA was extracted from peripheral blood by extraction kits to undergo polymerase chain reaction, traditional capillary electrophoresis sequencing and High-throughput sequencing so as to detect the mutations of deafness-related gene. RESULTS Among the 88 patients with NSHL, the gene mutation frequency was 34.09%.In the patients, 14 cases had mitochondrial 12 S rRNA mutations, six cases had GJB2 gene mutations and three cases had SLC26A4 mutations, two cases had MYO15A mutations, the other five cases had MYO7A, OTOF, TECTA, TMC1 and ILDR1 gene mutation respectively. CONCLUSION Among the 88 patients with NSHL, the most frequent mutation causing hereditary deadness was mutation in mitochondrial 12 S rRNA, followed by GJB2 and SLC26A4, The other genes such as MYO7A, OTOF, TECTA, TMC1 and ILDR1 gene were infrequent. The study could provide theoretical reference in genetic diagnosis, prevention and cure of hearing loss.

A Genetic AnaIysis of 800 Non-syndromic Deafness Patients from Shanxi Province / 听力学及言语疾病杂志

Objective The patients with non-syndromic deafness in Shanxi Province were retrospectively an_alyzed for the common deafness gene mutations and frequency of mutations carrying rate ,to understand the molecu_lar pathogenesis of deafness in Shanxi area .Methods Genomic DNAs of 800 patients of non -syndromic deafness within Shanxi were obtained from peripheral blood .Genes GJB2 ,GJB3 ,SLC26A4 and mitochondrial 12SrRNA 1494 and 1555 loci were sequenced after polymerase chain reaction (PCR) amplification and compared with the NCBI website for the analysis of the formation of mutations .ResuIts Among 800 patients ,353 cases (44 .13% ) showed detected deafness related mutations and the genetic etiology was found for 294 patients (36 .75% ) .Among them , 153 cases (19 .13% ) carried double allele mutations in the GJB2 gene .The most frequent mutation of GJB2 gene was 235delC ,and the carrying rate was 13 .5% (216/1 600) .The double mutant allele of SLC26A4 gene was detec_ted in 123 cases (15 .38% ) ,and the most common mutation was IVS7-2A>G ,identified in 7 .44% (119/1 600) of patients .Homogenic mitochondrial 12S rRNA 1494C> T mutation in one patient and 1555A> G mutation in 15 patients were detected .GJB3 gene c .538C > T heterozygous mutation was found in two patients .Altogether , 36 .75% (294/800) of patients with deafness were caused by gene mutations .ConcIusionThe data containing GJB2 gene and SLC26A4 gene carrying rate are consistent with the published data of non-syndromic deafness in the Northwest region of China ,but the carrying rate of mitochondrial gene mutations is lower than the average level of China .Our data show that the gene mutations contribute to 36 .75% of etiology in patients with deafness .This study reflects the importance of deafness related genes screening in Shanxi area for early diagnosis and genetic con_sultation .