Sequencing Analysis Of GJB2in Children With Deafness In Yunnan

Objective:Hearing loss is caused by genetic and environmental factors. About50%-60%of deafness cases have a genetic etiology. Genetic epidemiology studies showed that the most common mutation responsible for genetic deafness is GJB2. The children about the prevalence of GJB2were mainly made in the Chinese Han population living in the inner part of the China Mainland, while its research in Yunnan area is relatively small samples. So we investigate the molecular genetic causes of deafness, and analysis the mutation of GJB2gene coding region in deafness children of special education schools in Yunnan Province, in order to enrich the type and frequency of GJB2mutation as well as provide the important information to the pathogenesis of deafness.Methods:Under the informed consent, Genomic DNA was isolated from peripheral blood containing EDTA (2～3ml) of670students with hearing impairment and224non-deafness controls in7areas of Yunnan Province. GJB2gene coding region was tested by polymerase chain reaction (PCR) and direct sequencing method, which subsequently analyzed by DNAStar software.Results:4types of the GJB2gene coding region pathogenic mutations of670cases were detected including176dell6bp、235delC.299-300delAT and512insAACG. Their carrier frequency is176del16bp with0.15%,235delC with6.87%,299-300delAT with0.75%, and512insAACG with0.45%, respectively. Then, there are5kinds of common polymorphisms containing79G→A with total detection rate of49.10%;109G→A with8.06%;341A→G with29.40%,608T→C with2.39%, and478G→A with2.39%. On the other hand, there were no pathogenic mutation of GJB2in the control group, but finding3kinds of common polymorphisms with G79A、G109A and A341G.Conclusion:The pathogenic mutation rate of GJB2as well as the carrier frequency of235delC with deafness students in Yunnan special educational schools is below the average level of the general Chinese deaf population. The carrier frequency of GJB2235del C is the top one. The project can help elucidate the types and frequency of GJB2mutation, and provide scientific data for the genetic counseling, prevention and intervention of deafness...