Home > Browse Issues > Vol.38 No.2
Analysis of the Sequence Variants in GJB2 Gene Whole Coding Region for Patients and Their Pedigrees with Nonsyndromic Hearing Loss Detected by Screening of Newborns
Cao Ying1, Chen Jie2, Huang Rong1, Zhou Yurun2, Zhao Shengke1, Huang Ruili2, Fu Bifei3, Li Hongzhi1*
1School of Life Science/Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical University,Wenzhou 325000, China;
2People’s Hospital of Wenzhou City, Wenzhou Women and Child Health Care Institute,Wenzhou 325000, China;
3Wenzhou Medical College, School of 2nd Clinical Medicine, Wenzhou 325000, China
2People’s Hospital of Wenzhou City, Wenzhou Women and Child Health Care Institute,Wenzhou 325000, China;
3Wenzhou Medical College, School of 2nd Clinical Medicine, Wenzhou 325000, China
Abstract: To find deafness-causing mutations in GJB2 gene and explore the clinical manifestation of deafness of compound variants in GJB2 gene， the sequence variants in GJB2 gene whole coding region were analyzed for patients and their pedigrees with inherited nonsyndromic hearing loss detected by hearing screening of newborns in Wenzhou. Genomic DNA extracted from peripheral blood of 21 probands and their 57 family members was used in this study. The whole coding sequence of GJB2 gene was amplified by polymerase chain reaction (PCR).For the amplified products， 235delC mutation was screened by restriction fragment length polymorphism (RFLP)，then GJB2 sequence variations were determined by DNA sequencing， and the resultant GJB2 variants were further evaluated by bioinformatics analysis. The results demonstrated that the deafness-causing mutations in GJB2 gene were identified in 7 of the 21 pedigrees with nonsyndromic hearing loss， including the types of 235delC homozygote and 299-300delAT+109G>A compound heterozygote. In other 2 pedigrees， compound variants in GJB2 gene were found， which were probably pathologic， including 79G>A+109G>A+341A>G compound heterozygote and 79G>A homozygote+558G>A heterozygote， respectively. However， the results showed that compound heterozygote or compound homozygote 79G>A+341A>G， compound heterozygote 235delC+79G>A generally had not enough deafness-causing effect. The results proved that compound variants in GJB2 gene were frequently seen in patients with nonsyndromic hearing loss. Whether some variants in GJB2 gene could cause deafness significantly depended on genetic heterogeneity. Sometimes， polymorphisms might cause deafness when they were multiply combined.Environmental factors and genetic background may contribute to the clinical manifestation of deafness.
CN
EN