Application of Next Generation Sequencing Upon the Detection of Deafness Genes in Vietnamese Children with Non-syndromic Hearing Loss

Abstract

Introduction: There are 15000 hearing-impaired children are born in Vietnam every year. Early detection of common deafness mutations is a key factor for diagnosing, helping hearing-loss children to develop their language and awareness normally. Objective: To identify the carrier rate of common deafness mutations in Vietnamese population. Objects and Methods: 80 hearing-impaired and 100 normal children from Viet Nam. Apply technology of next generation sequencing to detect 100 mutations of 18 deafness genes, namely GJB2, GJB3, SLC26A4, MT-RNR1, MT-CO1, MT-TL1, MT-TS1, MT-TH, DSPP, GPR98, DFNA5, TMC1, MYO7A, TECTA, DIABLO, COCH, MYO15A and PRPS1. Result: The DNA microarray analysis revealed that identify 6 cases with deafness mutations (account for 10%). Identify by the next-generation sequencing method 18 mutations of deafness genes of 17 hearing-impaired patients (account for 22.5% in total), including 10 cases of mutations of genes GJB2 (8 heterozygous cases: c.299-300delAT, c.512insAACG, c.235delC and 2 homozygous cases: c.512insAACG); SLC26A4 (c.2168A>G, 3 cases); TMC1 (c.1334G>A); MT-RNR1 (m.827A>G, m.961delTinsC); MT-TH(m.12201T>C); MT-TL1 (m.3243A>G). No mutations were identified in the control group. Conclusion: The incidence of deafness mutations in hearing-loss group is 22.5%. Mutations of GJB2 cover the largest proportion (12.5%) among 18 genes investigated. In this review, we describe commonly used genomic technologies as well as the application of these technologies to the genetic diagnosis of deafness and to the discovery of novel genes for syndromic and nonsyndromic deafness.

Keywords

• NGS
• deafness
• GJB2
• TMC1
• SLC26A4
• MT-TH
• MT-TL1
• 12S rRNA