广西玉林特殊教育学校耳聋相关基因突变分析

Analysis of deafness-related gene mutations in hearing loss patients in Yulin special education school of Guangxi

目的分析广西玉林地区耳聋患者相关致病基因突变,初步了解玉林地区耳聋患者发病的分子机制。方法对玉林地区2个特殊教育学校191例耳聋患者进行分子病因信息采集,对6岁以上患者行纯音测听和声导抗进行听力评估;小于6岁的患儿行40 Hz相关电位、畸变产物耳声发射(distortion product otoacoustic emission,DPOAE)和听性脑干反应(auditory brainstem response,ABR)进行听力评估。采集外周血4 m L并提取基因组DNA,用耳聋基因微阵列芯片技术对4个致聋基因的9个突变位点(GJB2基因:c.35del G、c.235del C、c.176del16、c.299del AT;GJB3基因:c.538C>T;SLC26A4基因:c.919-2A>G、c.2168A>G;线粒体DNA 12Sr RNA基因:m.1494C>T、m.1555A>G)进行基因突变分析。结果在28例耳聋患者中检出GJB2、SLC26A4和线粒体DNA 12Sr RNA基因突变,总检出率为14.66%(28/191),其中GJB2基因c.235del C纯合突变3例,c.176_191del16和c.235del C复合杂合突变1例,c.235del C杂合突变2例,c.299_300del AT杂合突变合并SLC26A4基因c.919-2A>G杂合突变1例;SLC26A4基因c.919-2A>G纯合突变4例,c.919-2A>G杂合突变13例,c.919-2A>G和c.2168A>G复合杂合突变2例;线粒体DNA 12Sr RNA基因m.1555A>G均质突变2例。结论广西玉林地区耳聋患者热点突变基因以SLC26A4基因最为常见。玉林地区耳聋患者的相关基因检出阳性率、GJB2基因、SLC26A4基因及线粒体DNA 12Sr RNA基因的携带率均低于全国平均水平。

Objective To identify the deafness-related gene mutations in patients with hearing loss in Yulin,and to explore the molecular pathogenic mechanism.Methods Patients＇ information was collected and blood samples were obtained from 191 patients with hearing loss from a special education school.Patients6 years of age or older were evaluated by pure tone audiometry and acoustic immittance.Patients less than 6years old were evaluated by 40 Hz auditory event related potential,distortion product otoacoustic emission（DPOAE） and auditory brainstem response（ABR）.Genomic DNA samples of 191 deafness patients were extracted from peripheral blood.9 mutations of 4 genes（including c.35 del G,c.235 del C,c.176del16,c.299 del AT in GJB2 gene;c.538C〉T in GJB3 gene;c.919-2A〉G and c.2168A〉G in SLC26A4 gene;m.1494C〉T and m.1555A〉G in mt DNA 12 Sr RNA gene） were detected with the gene chip technique.Results Among191 patients with hearing loss,28 cases were found to carry at least one pathogenic gene mutation.The positive detection rate was 14.66%（28/191）.In these patients,7 cases had GJB2 gene mutations（c.235 del C homozygous mutation in 3 cases,c.176_191del16/c.235 del C compound heterozygous mutation in 1 case,c.235 del C heterozygous mutation in 2 cases,c.299_300del AT/c.919-2A〉G compound heterozygous mutation in 1 case）;19 cases had SLC26A4 gene mutations（c.919-2A〉G homozygous mutation in 4 cases,c.919-2A〉G heterozygous mutation in 13 cases,c.919-2A〉G/c.2168A〉G compound heterozygous mutation in 1 case） and 2 cases had mitochondrial DNA 12 Sr RNA m.1555A〉G mutations.Conclusion SLC26A4 gene mutations are the most common hot spot mutations in deafness patients in the Yulin area.Incidence of GJB2,SLC26A4 and mitochondrial DNA 12 Sr RNA gene mutations in the deafness population in Yulin is below the average of the overall Chinese deaf population.