陕西省800例非综合征型聋患者常见致聋基因突变分析

A Genetic Analysis of 800 Non-syndromic Deafness Patients from Shanxi Province

目的分析陕西省非综合征型聋患者常见耳聋基因突变方式及频率,了解其耳聋发病的分子机制。方法采集陕西省800例非综合征型聋患者外周血,提取基因组DNA,采用聚合酶链式反应(PCR)扩增GJB2基因、GJB3基因、SLC26A4基因以及线粒体12SrRNA 1494和1555位点进行直接测序,序列与NCBI网站公布的标准序列进行比对分析。结果 800例非综合征型聋患者中,共353例(44.13%)患者携带耳聋致病基因突变,其中153例(19.13%)携带GJB2基因双等位基因突变,GJB2基因最常见的突变方式为235delC,检出率为13.5%(216/1 600);123例(15.38%)携带SLC26A4基因双等位基因突变,SLC26A4基因最常见突变方式为IVS7-2A>G,检出率为7.44%(119/1 600);1例携带线粒体12SrRNA1494C>T均质性突变,15例携带1555A>G均质性突变;2例患者携带GJB3基因c.538C>T杂合突变。294例(36.75%,294/800)患者由上述基因突变导致耳聋。结论陕西省非综合征型聋患者中,GJB2基因以及SLC26A4基因的突变携带率与全国以及西北地区平均水平较为一致,而线粒体基因突变的携带率偏低。

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 .