Mutation Analysis of GJB2 Gene of Young Deaf Population of Swat Pakistan

Hearing loss is one of the most common sensory disorders in human population worldwide. It is caused by many environmental and genetic factors, genetic factors being most important. Many genes are involved in hearing mechanism, GJB2 gene is one of such genes. The GJB2 gene encodes for connexin 26 proteins which helps the potassium K + ions recycling in the inner ear cells. So far over hundred mutations linked with hearing loss in GJB2 gene have been found. The most frequent mutations include 35delG, 167delT , 235delC etc. These mutations change the gene sequence which results in the production of abnormal proteins and consequently a failure in the hearing process. Material and methods: In present study, Genomic DNA was isolated from liquid saliva of 54 samples by modified phenol-chloroform method. A 791bp fragment of exon II was amplified by Polymerase Chain Reaction. After the gel electroporation the cutted bands were verified by the analysis of nucleotide sequence of both strands and comparison of consensus sequence with GJB2 gene sequence available in the gene bank. Results: It shows that three individuals out of 54 have 9 mutations i.e G196A,G296A, G372A, T345C, A346T, A347T, G348C, G349A and G374A, changing the structural confirmation of Cx26 protein. This shows a prevalence percentage of about 5.55% in relation to GJB2 gene disorders. Conclusion: Our research work support the concept that there is relation of JGB2 gene with Hearing loss, in our study the prevalence rate of mutation in JGB2 gene of deaf patients is 5.5%.