ABSTRACT
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 .