一个母系遗传非综合征耳聋大家系mtDNA序列分析

Mitochondrial DNA Sequence Analysis of an Extensive Matrilineal Nonsyndromic Deafness Pedigree

通过分析本家系mtDNA序列 ,探讨淮阴一非综合征耳聋大家系患病的分子遗传学机制。采用聚合酶链反应 (PCR)扩增mtDNA与非综合征耳聋相关位点nt15 5 5、nt744 5的区域和人类种群研究的D -loop区、PCR -异源双链分析、PCR -RFLP、PCR产物克隆序列测定等技术对该家系进行了系统的研究。发现该家系中全部母系亲属有mtDNAA15 5 5G突变 ,而家系中非母系个体、对照组 (10 0例正常个体 )的mtDNA 15 5 5位点均为A。该家系mtDNA 744 5位点无突变 ;该家系属于II型线粒体 ;发现家系D -loop区存在未见报道的碱基插入。提示mtDNAA15 5 5G位点突变可能是导致该家系患者致聋的主要因素之一。遗传背景可能对家系疾病的表型存在一定程度的影响。

We find an extensive nonsyndromic sensorineural deafness family in Huaiyin, and investigate the possible molecular genetic mechanism of matrilineal nonsyndromic sensorineural deafness. We use PCR,combined with PCR-heteroduplex analysis, PCR-RFLP and sequencing techniques to examine part of 12S rRNA, tRNAser(UCN),and D-loop region of this pedigree. 1) We found an A to G transition at position 1555(A1555G) of the mitochondrial 12S rRNA from all the patients and four matrilineal. 2). An new nucleotide insertion was indentified in D-Loop region. 3) According to the polymorphism of D-loop, this pedigree belong to mitochondrial type II. This study showed that the A1555G mutation may be one of major factors in progressive inherited deafness of this family and genetic background should be investigated in the future.