一个遗传性非综合征型耳聋家系的 GJB2基因突变分析

目的：对1个遗传性非综合征型耳聋家系的临床表型特征进行分析，并选取 GJB2基因进行突变检测。方法详细询问病史和临床检查后，提取患者及家系成员的外周血基因组 DNA ，PCR 扩增 GJB2基因的外显子及外显子和内含子的交界区域，然后对扩增产物进行 DNA 测序和 BLAST 比对进行突变分析。结果该家系所有患者为迟发性、渐进性、早期以高频听力下降为主的感觉神经性聋。 GJB2基因突变分析检测到6种单核苷酸多态，其中 c ．79G ＞ A （p ．Val27Ile）和 c ．341G ＞ A （p ． Glu114Gly）为已知单核苷酸多态，而位于3′‐UTR 的 g ．4159T ＞ C 、g ．5142G／T 、g ．5227G／A 、g ．5352T ／C 突变为本研究新发现。结论该家系未发现 GJB2外显子致病性突变，遗传性非综合征型耳聋存在明显的遗传异质性。

Mutational analysis of GJB2 gene in a Chinese family with nonsyndromic hearing loss

Objective To analyze the clinical and genetic features of a Chinese family with nonsyndromic hearing loss ,and to find deafness‐causing mutations in the GJB2 gene .Methods After a detailed history and clinical examination ,genomic DNA was ex‐tracted from peripheral blood for the proband and their family members .Two exons of the GJB2 gene was amplified by polymerase chain reaction ,and the PCR products were subjected to automatic DNA sequencing .Finally ,the mutation analysis was performed by SeqMan software of DNASTAR to compare BLAST .Results All patients in this family had late‐onset and progressive hearing loss and ultimately involved all frequencies .Six SNP polymorphisms were found in this pedigree ,which were previously reported world‐wide ,c .79G > A(p .Val27Ile) ,c .341G > A(p .Glu114Gly) ,were also identified in this family .Four single nucleotide polymorphisms (SNPs) were firstly identified in the GJB2 3′‐UTR ,including g .4159T > C ,g .5142G/T ,g .5227G/A ,g .5352T /C .Two SNPs .Con‐clusion Mutation in exons of GJB2 gene was excluded as a pathogenic cause for nonsyndromic hearing loss in this family .