大同市特教学校非综合征性聋分子病因学分析--GJB2 235delC突变和线粒体DNA 12SrRNA A1555G突变筛查报告

目的 进行山西省大同地区重度耳聋的分子流行病学调查。方法 对山西省大同市特殊教育学校152名耳聋学生进行遗传性耳聋问卷调查、全面的体格检查、耳鼻咽喉专科检查以及包括纯音测听和声导抗在内的听力学评估。对148名非综合征型感音神经性耳聋患者分别进行线粒体DNA 12SrRNA基因A1555G点突变和GJB2基因235delC突变的限制性内切酶分析。结果 3例（2．03％）存在线粒体DNA 12SrRNA基因A1555G点突变，16例（10．8l％）存在GJB2基因235delC纯合突变，2l例（14．19％）存在GJB2基因235delC杂合突变，能够明确进行基因诊断者占27．03％。结论 山西省大同地区非综合征型耳聋患者存在较高的GJB2基因235delC突变发生率．而线粒体DNA 12SrRNA基因A1555G突变发生率低于全国平均水平。通过聋病分子流行病学调查．提示27．03％的非综合征型耳聋患者具有明确或强烈的遗传倾向，对于大同地区耳聋的预防、治疗及康复有着较好的意义。

Molecular genetic analysis of GJB2 gene and mtDNA12SrRNA A1555G mutations in severe to profound hearing loss patients in Datong City, Shanxi Province of China

Objective To conduct a molecular epidemiological survey of non-syndromic hearing loss in Datong, Shanxi Province. Methods 152 deaf-mute school students and their parents and teachers were interviewed to identify medical histories of hearing loss, exposure to aminoglycosides, and other clinical abnormalities by filling a questionnaire. The otological, audiological and neurological examinations of these patients were conducted, including otoscopy, pure-tone (Madsen 522) and immittance (GSI 33) audiometry. MtDNA A1555G mutation and GJB2 235delC mutation were detected with specific restriction enzyme digestion methods. Results Three of 148 cases with non-syndromic hearing impairment (NSHI) were found to carry mtDNA A1555G mutation, 16 cases were detected to have homozygous GJB2 235delC mutation and 21 cases were detected to have heterozygous GJB2 235delC mutation. Conclusions High incidence of GJB2 235delC mutation was detected in the deaf population of Datong, Shanxi Province, while the incidence of mtDNA A1555G is lower than the average level in the general Chinese deaf population. Among students with NSHI in deaf-mute school in Datong about 27.03% were classified with hereditary hearing loss by genetic testing.