基于GJB2235de1C单杂合突变致聋的GJB2基因上游调控区的序列分析

发布时间：2018-03-31 22:29

本文选题：GJB2基因　切入点：12SrRNA基因突变　出处：《南京医科大学》2013年硕士论文

【摘要】：第一部分：非综合征型耳聋患者GJB2基因及线粒体DNA12S rRNA基因突变分析目的：通过对非综合征型耳聋患者进行GJB2基因及线粒体DNA12SrRNA基因的突变检测，了解其突变类型和突变频率，为进一步指导聋病基因筛查和遗传咨询提供理论依据。方法：收集190例门诊非综合征耳聋患者的外周血样，常规法提取基因组DNA。PCR扩增GJB2基因编码区及线粒体DNA12S rRNA目的片段，对纯化后的目的片段进行测序分析，识别耳聋相关的致病突变。结果：190例患者中，，128例携带GJB2突变，共23种突变类型，其中已知的致聋突变5种，以235delC为主（16.32%）；发现42个线粒体DNA12SrRNA突变位点，43种突变类型，其中明确与非综合征型耳聋相关的致病突变3种：C1494T, A1555G和961位点突变，以A1555G为主（6.32%）。检测出GJB2单杂合致聋突变携带率者25例（13.16%），其中235delC单杂合突变携带者14例（7.37%）。5名患者同时携带GJB2235delC单杂合突变和线粒体DNA12SrRNA突变。结论：GJB2基因和线粒体DNA12S rRNA基因是我国非综合征型耳聋患者的突变热点基因，针对上述基因的突变筛查有助于明确耳聋的分子病因。鉴于GJB2235delC单杂合突变携带率较高，进一步研究其致聋机制是必要的。第二部分：GJB2235delC单杂合突变耳聋患者的GJB2基因上游调控区序列分析目的：探讨GJB2基因上游调控区的序列变化与该基因编码区235delC单杂合突变致聋的相关性。方法：对实验室前期确定的14例携带GJB2235delC单杂合突变的耳聋患者、20例未发现致病突变的耳聋患者及25例听力正常个体进行GJB2基因上游调控区序列的PCR扩增及测序分析。结果：在14例GJB2235delC杂合突变耳聋患者中检测到两种碱基变异-843AC和-195TC，结合对照组检测结果，基本可确定两者均为多态性改变。结论：GJB2基因上游调控区序列的改变可能不是协同该基因编码区突变致聋的常见分子事件。
[Abstract]:Part I: mutation analysis of GJB2 gene and mitochondrial DNA12S rRNA gene in patients with non-syndromic deafness. Objective: to investigate the mutation types and frequencies of GJB2 gene and mitochondrial DNA12SrRNA gene in patients with non-syndromic deafness, and to provide theoretical basis for gene screening and genetic counseling of deafness. Methods: peripheral blood samples were collected from 190 patients with non-syndromic deafness. Genomic DNA.PCR was extracted to amplify the coding region of GJB2 gene and the target fragment of mitochondrial DNA12S rRNA, and the purified fragment was sequenced. Identify deaf-related mutations. Results among the 190 patients, 128 had GJB2 mutations, including 23 mutation types, 5 of which were known deafness mutations, mainly 235delC 16.322.43 mutations were found in 42 mitochondrial DNA12SrRNA mutation loci. Among them, there were 3 kinds of mutations at the 1: C1494T, A1555G and 961 loci that were specifically associated with non-syndromic deafness. 25 cases with GJB2 single heterozygous deafness mutation were detected, among which 14 patients with 235delC single heterozygous mutation carried GJB2235delC monozygosity mutation and mitochondrial DNA12SrRNA mutation at the same time. Conclusion the gene of: GJB2 and mitochondrial DNA12S rRNA are the hot mutation genes in non-syndromic deafness patients in China. The mutation screening of these genes is helpful to clarify the molecular etiology of deafness. In view of the high rate of single heterozygosity of GJB2235delC, It is necessary to further study the mechanism of deafness. Part two: sequence analysis of upstream regulatory region of GJB2 gene in deafness patients with single heterozygous mutation GJB2235delC. Aim: to investigate the relationship between the sequence change of upstream regulatory region of GJB2 gene and the deafness caused by 235delC single heterozygosity mutation in the coding region of GJB2 gene. Methods: PCR amplification and sequencing analysis of the upstream regulatory region of GJB2 gene were performed in 14 deafness patients with single GJB2235delC heterozygosity and 25 hearing normal individuals. Results: two kinds of base mutation -843AC and -195TC were detected in 14 patients with GJB2235delC heterozygous deafness. Conclusion the change of the upstream regulatory region of the gene may not be a common molecular event of deafness caused by the mutation in the coding region of the gene.
【学位授予单位】：南京医科大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R764.43

【参考文献】