青海省回、藏、土、蒙古族非综合征型聋患者致聋基因SNPscan法检测分析

目的：调查 GJB2、SLC26A4和mtDNA12SrRNA基因突变在青海省回、藏、土、蒙古族非综合征型聋患者中的突变谱和突变频率。方法采集青海省回族（123例）、藏族（44例）、土族（34例）及蒙古族（10例）共211例非综合征型聋患者及180例正常人（对照组，其中回族100例，藏族40例，土族30例，蒙古族10例）的外周静脉血，提取基因组DNA，应用SNPscan法检测GJB2基因2个外显子36个突变位点、SLC26A4基因21个外显子77个突变位点和mtDNAA1555G及mtDNAC1494T突变。结果211例耳聋患者中，5例土族和1例蒙古族患者携带mtDNAA1555G均质性突变；回族、藏族、土族和蒙古族患者 GJB2基因突变检出率分别为11．38％、4．55％、5．88％和10％，各民族间差异无统计学意义（均为P＞0．05）。土族和蒙古族耳聋患者GJB2基因最常见的突变形式为c．235delC，等位基因频率分别为2．94％和5％；回族耳聋患者最常见的突变形式为 c．299300delAT，等位基因频率为4．47％。回族、藏族和土族患者SLC26A4基因突变检出率分别为6．5％、4．55％和2．94％，三个民族间差异无统计学意义（均为P＞0．05）；回族耳聋患者SLC26A4主要突变为c．919－2A＞G，等位基因频率为2．44％；藏族耳聋患者SLC26A4的主要突变为c．1226G＞A，等位基因频率为2．27％。正常对照组除了回族中有1例携带GJB2基因c．235delC杂合突变，1例携带SLC26A4基因c．919－2A＞G中等位基因突变，其余三个民族均未检测出GJB2、SLC26A4基因突变。结论青海省回、藏、土及蒙古族非综合征型聋患者中10．9％（23／211）是由GJB2、SLC26A4和mtDNA A1555G基因突变导致，GJB2和SLC26A4基因突变在该地区4个少数民族非综合征型聋患者中的致病具有民族特异性。

The Mutation Analysis of Common Deafness Genes Using SNPscan Technology in Nonsyndromic Hearing Loss Patients of Minority Ethnicities in Qinghai Province

Objective This study aims to investigate the mutation spectrum and frequency of GJB2 , mtDNA12SrRNA,and SLC26A4 genes in Hui people,Tibetan,Tu nationality,and Mongolian patients with non-syndromic hearing loss in Qinghai province.Methods Peripheral blood samples were obtained from a total of 211 minority patients with nonsyndromic hearing loss in Qinghai province to extract genomic DNA.Three genes of GJB2,mitochondrialDNA12SrRNA,and SLC26A4 were screened for mutations in our study cohort using SNPscan technology.Results Among these 211 patients,5 Tu patients and 1 Mongolian patient were found to carry the ho-moplasmic mtDNAA1555G mutation.The GJB2 mutations detection rates were 11.38%,4.55%,5.88%,and 10%in Hui people,Tibetan,Tu nationality,and Mongolian patients,respectively.No statistically significant differences in the GJB2 mutations detection rates were found among all four ethnicities (P>0.05).c.235delC was the most prevalent mutation in both Tu patients and Mongolian patients.The allele frequency was 2.94% and 5%,respec-tively.While for Hui patients,c.299 300delAT was the most prevalent mutation with the allele frequency of 4.47%.The mutations detection rates of SLC26A4 were 6.5%,4.55%and 2.94%in Hui people,Tibetan,and Tu nationality patients,respectively.No statistically significant differences in the SLC26A4 mutations detection rates were found among all three ethnicities (P>0.05).c.235delC was the most prevalent mutation in Hui patients,the allele frequency was 2.44%.While for Tibetan patients,c.1226G>A was the most prevalent mutation with allele frequency of 2.27%.Conclusion A total of 10.9% of deaf patients have inherited hearing impairment caused by GJB2,SLC26A4,and mtDNAA1555G mutations.The mutation spectrum of GJB2 and SLC26A4 genes has the eth-nic specificity in nonsyndromic hearing loss patients of minority ethnicities in Qinghai province.