应用基因芯片技术对一近亲婚配耳聋家系致聋机制的分析

Study on the causes of deafness in a consanguineous marriage family using DNA microarray

目的:在DNA水平上对一个非综合征型耳聋家系进行耳聋易感基因的突变筛查,确定家系成员的致病基因及分型。方法:收集家系成员外周血,提取DNA进行等位基因多重PCR,基因芯片杂交筛查GJB2、GJB3、PDS和mtDNA 12SRNA基因突变,DNA测序验证基因芯片结果。结果:先证者为GJB2基因235delC和299-300delAT复合杂合,其父母分别为GJB2基因235delC和299-300delAT纯合突变基因型,父系亲属中耳聋者均为299-300delAT纯合突变基因型,听力正常成员为杂合基因型,该致病基因来源于近亲婚配祖父母。结论:GJB2基因突变是导致该家系发生耳聋的致病因素,耳聋基因芯片检测是确定遗传性聋病因的必要手段。

Objective：To determine the possible gene mutation and its different sites that leads to hearing loss in a consanguineous marriage pedigree.Method：Blood samples from a Changchun pedigree were obtained with informed consent.Their genomic DNA were extracted from peripheral blood and PCR was performed.Nine of hot spot mutations in four most common deafness pathologic gene were detected with the DNA microarray,including GJB2,GJB3,PDS and mtDNA 12S RNA gene.At the same time,the results were confirmed with the traditional methods of sequencing.Result：GJB2 gene of 235 delC and 299-300 delAT compound heterozygous mutation was found in propositus.His father was 299-300 delAT homozygous mutation and mother was 235 delC homozygous mutation.In the relatives on the paternal side,the affected patients all were 299-300 delAT homozygous mutation and normal hearing member was 299-300 delAT heterozygous carrier.This GJB2 mutation come from grandparents of consanguineous marriage.Conclusion：GJB2 gene mutation played on an important role in this deafness family.It is essential approach for genetic diagnosis of non-syndromic sensorineural hearing loss.