河北涿州、高碑店市特教学校非综合征性聋分子病因学分析——GJB2 235delC突变、SLC26A4 IVS7-2A＞G突变和线粒体DNA12SrRNA A1555G突变筛查报告

目的 对河北涿州、高碑店地区重度耳聋患者进行分子流行病学调查，了解耳聋的常见分子病因。方法 对河北涿州、高碑店市特殊教育学校64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听力学评估（包括纯音测听和声导抗）。对64名非综合征型感音神经性耳聋患者分别进行GJB2基因235delC突变、线粒体DNA 12SrRNA基因A1555G点突变的限制性内切酶分析。应用直接测序法检测SLC26A4基因IVS7—2A〉G突变。结果7例（10．93％）携带GJB2基因235delC纯合突变；9例（14．06％）携带GJB2基因235delC杂合突变；6例（9．37％）携带SLC26A4基因ⅣS7—2A〉G纯合突变，12例（18．75％）携带SLC26A4基因IVS7—2A〉G杂合突变：未发现携带线粒体DNA 12SrRNA基因A1555G点突变者。结论 河北涿州、高碑店地区非综合征型耳聋患者存在较高的GJB2基因235delC和SLC26A4基因ⅣS7—2A〉G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。聋病分子流行病学调查提示河北涿州、高碑店地区20.3％的非综合征型耳聋患者在分子水平能够明确诊断．另有32．81％的患者有遗传倾向。进行准确的耳聋早期诊断、遗传咨询、及时干预和治疗在这一地区的聋哑人群中非常重要。

Screening of GJB2 235de1C mutation,SLC26A4 IVS7-2A＞G mutation and mtDNA 12SrRNA A1555G mutation in severe-profound hearing loss patients in Zhuozhou and Gaobeidian,Hebei province

Objective To conduct a molecular epidemiological survey of non-syndromic hearing loss in Zhuozhou and Gaobeidian,Hebei province. Methods Sixty-four deaf students were interviewed to identify medical histories of hearing loss,the use of aminoglycosides,and other clinical abnormalities by filling a questionnaire. The audiological and neurological examinations of these patients were conducted,including otoscopy,pure-tone audiometry(Madsen 522) and immittance (GSI 33). GJB2 235delC mutation and mtDNA A1555G mutation were detected with specific restriction enzyme digestion methods. Results None of the 64 cases with non-syndrome hearing impairment(NSHI) carried mtDNA A1555G mutation,7 cases had homozygous GJB2 235delC mutation and 9 cases had heterozygous GJB2 235delC mutation. Six cases carried homozygous SLC26A4 IVS7-2A>G mutation and 12 cases had heterozygous SLC26A4 IVS7-2A>G mutation. Conclusion A high incidence of GJB2 235delC and SLC26A4 IVS7-2A>G mutations was found in the deaf population of Zhuozhou and Gaobeidian,Hebei province,while the incidence of mtDNA A1555G is lower than the average level of the overall Chinese deaf population. In Zhuozhou and Gaobeidian,20.3% of NSHI were confirmed to be hereditary hearing loss and additional 32.81% were suggested to be hereditary hearing loss by genetic screening.