贵阳市盲聋哑学校非综合征性耳聋分子病因学分析——GJB2 235delC突变和线粒体DNA 12SrRNA A1555G突变筛查报告

目的 进行贵州省贵阳地区非综合征性耳聋分子病因学调查。方法 对贵阳市盲聋哑学校150名聋哑学生进行耳聋病因问卷调查、纯音听阈测试，对其中139名非综合征性耳聋患者进行线粒体DNA 12SrDNA A1555G点突变和GJB2基因235delC突变限制性内切酶的分析。结果 139名非综合征性耳聋患者中。6例（4132％）存在线粒体DNA 12SrDNA A1555G点突变；17例（12．23％）存在GJB2 235delC纯合突变；9例（6．47％）存在GJB2235delC杂合突变，在分子水平能够明确诊断者占23．02％。结论 贵阳地区耳聋患者存在较高的遗传性耳聋发生率，线粒体DNA A1555G突变发生率和GJB2 235delC突变发生率均高于全国平均水平。耳聋基因诊断技术可以应用在地区性耳聋病因调查中进行快速筛查、诊断，并可达到防止再出生聋儿，指导聋儿康复等积极效果。

Analysis of GJB2 gene 235delC and mtDNA A1555G mutations in non-syndromic severe-profound hearing loss patients in Guiyang city,Guizhou province of China

Objective To determine the prevalence of GJB2 235delC and mitochondrial DNA(mtDNA)A1555G mutations in non-syndromic severe-profound hearing loss patients at the Deaf-Blind School in Guiyang city,Guizhou province. Methods The peripheral blood samples were obtained and DNA templates were extracted by extraction kits. Using polymerase chain reaction(PCR),the code region of GJB2 gene was amplified. The GJB2 235delC mutation was distinguished by Apa1 restricted enzyme digestion method. The Genetic Testing Kit for Mitochondrial DNA A1555G Mutation was used to detect the mtDNA A1555G mutation. Results Among 139 patients with non-syndromic hearing loss,GJB2 235delC was found in 26 cases (17 cases were homozygosis,9 cases were heterozygosis); 6 cases were shown to carry the mtDNA A1555G mutation. Conclusion The incidence of GJB2 gene and mtDNA A1555G mutations among the deaf-mute students in Guiyang city is 23.02%. Molecular genetic screening for these mutations and genetic counseling are effective methods to prevent the occurrence of hereditary hearing loss.