Identification And Analysis A New Mutation Of The SLC26A4 Gene In A Family Of Large Vestibular Aqueduct Syndrome

Objective:SLC26A4 gene,a common deafness gene,is considered to be closely related to the incidence of Large Vestibular Aqueduct Syndrome?LVAS?and Pendred syndrome?PS?.In this paper,the clinical detection of a large vestibular aqueduct syndrome patient in our hospital was conducted to determine its clinical disease,and then the peripheral blood of the family was collected and DNA sequencing was collected to detect the mutation site of the pathogenetic SLC26 A4 gene,and to find its molecular etiology.We detected the gene mutation of the SLC26A4 gene and found its molecular etiology.The purpose of this study is through the examination of clinical audiology and imaging,combined with gene mutation detection and other related inspection,to determine the deafness caused by new SLC26A4 gene mutation,so that we can have a system understanding of large vestibular aqueduct syndrome from the clinical symptoms to pathogeny.Methods:The family members' health status,history of trauma and the history of otitis media were investigated,and physical examination was carried out.Pure tone audiometry and vestibular function examination,temporal bone CT and other imaging examinations were performed for congenital deafness patients.The peripheral venous blood samples?6ml?of the family members were collected,genomic DNA were extracted,using polymerase chain reaction?PCR?amplified the extracted DNA,and the amplified products were purified.Detected new gene mutations by Sanger gene sequencing,and compared amino acid domain to other species to validate their conservative.Results:The family proband had bilateral sensorineural hearing loss.The left ear was completely deaf,and the right ear was extremely severe sensorineural hearing loss.The temporal bone CT showed bilateral vestibular aqueduct enlargement?>1.5?.Cochlear implantation for the patients.The new mutation of SLC26A4 gene is found to be a compound heterozygous mutation:c.1207₁208GC>TT,which results in the substitution of GCC?alanine?at TTC?phenylalanine?at 403 amino acid sites.The father carries the new gene mutation:c.1207₁208GC>TT,the mother carries the c.919-2A>G gene mutation.The mutation of the c.919-2A>G gene is the mutant site that has been reported.Their two children carry the compound heterozygous mutation c.919-2A>G and c.1207₁208GC>TT,has the similar symptom.Conclusions:Our results showed that the SLC26A4 gene mutation was related to hearing loss in the family.And we found a new gene mutation site,c.]207₁208GC>TT,in the SLC26A4 gene,which,together with c.919-2A>G,leads to the large vestibular aqueduct syndrome.Therefore,early and timely examination and treatment are of great help to the diagnosis and prognosis of the patients and the improvement of the quality of life.