WFS1基因异质性突变致遗传性耳聋表型差异的发病机制研究

项目名称： WFS1基因异质性突变致遗传性耳聋表型差异的发病机制研究

项目编号： No.30872864

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 刘玉和

作者单位： 北京大学

项目金额： 31万元

中文摘要： 本课题研究遗传性耳聋的致聋基因突变以及突变基因的致聋机制。在两个常染色体显性遗传性耳聋家系中采用全基因组扫描，SNP连锁分析的方法连锁分析获得耳聋家系相关基因的定位，分别定位于9号染色体和4号染色体。然后采用全基因组外显子捕获技术结合相关基因定位区间内全部基因功能分析，确定DFNB31基因是一个常显家系的致病基因，其基因错义突变导致氨基酸的改变，通过软件分析确定该突变改变了dfnb31蛋白的空间结构和激酶功能。进一步研究突变基因的致聋机理包括通过免疫组织化学法检测WFS1基因在鼠耳蜗组织和听觉中枢的表达分布，然后分别检测低频遗传性聋患者与正常听力者的成纤维细胞中wolframin蛋白的含量。通过分析不同突变型WFS1基因编码蛋白的稳定性以及对耳蜗不同部位细胞功能的影响，结合临床听力学特点，揭示突变致遗传性聋表型差异的机制。本研究一方面确定了两个常染色体显性遗传性耳聋家系的致聋基因，另一方面也揭示了WFS1基因异质性突变致遗传性耳聋表型差异的机制。本研究将对进一步研究同一基因不同突变致不同遗传表型的致聋机制研究具有重要的意义。

中文关键词： 遗传性聋；基因突变；蛋白；机制

英文摘要： The objective of the present project was to find the mutations of related gene with hereditary hearing loss and to study the mechanism of mutant gene resulting in hearing loss. In the two pedigrees with autosomal dominant hereditary deafness, whole genomes scanning and SNP linkage analysis were applied to position the related gene, and the related genes were located in the chromosome 9 and chromosome 4 respectively. Then exon capture technology in the whole genome was used to sequence the target part, DFNB31 gene was a deafness related gene in one pedigree. The missense mutation of DFNB31 gene was found in a pedigree, resulted in the amino acids change. It was identified that the mutations changed spatial structure and function of DFNB31 protein kinase, through the software analysis. Further research of the mechanism, that the mutation cause hearing loss, included that WFS1 gene expression distribution in rat cochlear tissue and hearing center tissue was detected through immunohistochemistry, then wolframin protein content was detected in fibroblast tissue in patients with low frequency genetic deafness and the normal hearing respectively. Through the analysis of different type WFS1 gene mutations and the stability of the mutant wfs1 protein, combined with clinical audiologic characteristics, the mechanism of genetype-phenotype relationship was clarified. On one hand, this study determined deaf related gene in the two pedigrees with autosomal dominant hereditary hearing loss. On the other hand, it also revealed the mechanism that the heterogeneity mutation of WFS1 gene cause different deafness phenotype. It was important that the conclusion in this study to research the different mutation in one gene resulted in different phenotype.

英文关键词： genetic hearing loss; mutation of gene; protein; mechanism