Waardenburg 综合征MITF基因c.328T>C突变的分子致病机制研究

项目名称： Waardenburg 综合征MITF基因c.328T>C突变的分子致病机制研究

项目编号： No.81200752

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 医学二处

项目作者： 杨淑芝

作者单位： 中国人民解放军总医院

项目金额： 23万元

中文摘要： MITF基因突变与Waardenburg 综合征(WS)密切相关，但其确切的分子致病机制目前尚未阐明，尤其是对携带相同基因突变的不同个体临床表型具有高度异质性的现象目前尚无相关定论。本课题在一中国WS2型家系中首次检测到MITF基因c.328T>C 突变，携带这一突变的个体在耳聋、皮肤及毛发色素分布异常、虹膜异色表型上具有高度的临床异质性，并且还发现了罕见的临床表型正常的携带者，这与MITF基因的显性致病学说相左。为揭示这一现象的内在原因，课题组拟在前期工作的基础上，在中国WS群体中进行MITF基因c.328T>C突变筛查；同时综合运用定量PCR技术、免疫印迹技术、重亚硫酸盐测序技术等手段对MITF基因在家系个体中的表达规律及表观遗传状态进行分析，探讨突变个体间表型异质性的机制；通过构建突变及野生型基因表达载体对MITF基因c.328T>C突变效应进行分析，揭示突变致病的分子机制。

中文关键词： Waardenburg 综合征；基因突变；转录因子；突变体；转录活性

英文摘要： MITF gene point mutations were identified in Waardenburg syndrome (WS) type 2 patients, and thought to be disease-causing gene mutations. but the exact molecular pathogenic mechanism is not known. Above all, highly clinically heterogeneous were observed in different individuals, who were identified with identical gene mutations. In this study, we identified a novel mutation c.328T>C (p.Arg110X) of MITF gene in a Chinese pedigree with WS type 2. All the affected individuals manifested a highly phenotypic variations in deafness, abnormal pigment disturbances of skin and hair, and heterochromia irides. Moreover, a single unaffected family member was also detected this mutation. It was deviated from the dominant pathopoiesis of MITF gene. In order to reveal the possible molecular pathogenic mechanism, we will carry out MITF gene c.328T>C mutation screening analysis in WS patients, and analyze the gene expression of MITF and epigenic status in different individuals combined with quantified PCR , immunoblot assay, bisulfite-modification directed PCR product sequencing technique. we will investigate the possible mutation effect of c.328T>C by construction and fuctional study of wild and mutant of MITF gene, and try to interpret the possible pathogenic mechanism of WS.

英文关键词： Waardenburg syndrome；gene mutation；transcription factors；mutant；transcriptional activity