In-depth Study Of GJB2 Gene Mutation Site Based On The Follow-up Results Of Newborn Deafness Gene Screening In Zhengzhou

Background Studies at home and abroad have shown that 60% of deafness is caused by genetic factors,70% of which is non syndromic deafness.At present,many genes and mutation sites related to non syndromic deafness have been found.It is of great significance for large-scale screening and diagnosis of deafness to understand these specific gene information and detect mutation sites.During the work of newborn deafness gene screening project in Zhengzhou in 2018,it was found that the detection results of some samples were heterozygous mutations of GJB2 gene unit point,but the follow-up results were patients with congenital deafness.It was speculated that there might be other rare deafness sites on GJB2 gene in these patients.Objective Through the in-depth study of GJB2 gene,we can find the rare pathogenic mutation beyond the scope of deafness gene screening and detection,explore the cause of congenital deafness of patients,provide the basis for the subsequent diagnosis and treatment of patients,guide the marriage and childbearing of patients and their relatives,and provide the research basis for the optimization and upgrading of detection methods of newborn deafness gene screening project and the research and development of new products,in order to improve the detection rate of congenital deafness.Method 11 patients with the above conditions were selected to sequence and analyze the GJB2 gene full coding region by the first generation sequencing technology,so as to find out the rare pathogenic mutation sites beyond the scope of deafness gene screening and detection,and determine the pathogenicity of the mutation sites through the deafness gene database and literature research.Result In addition to the common deafness mutations,8 samples were also tested for c.109 g > a heterozygous mutations,and c.257 c > G,c.512₅13ins 4 ? c.313₃26del14 heterozygous mutations.Subsequently,through the research of deafness gene database and literature data,it is confirmed that these four mutations are all deafness mutations,which form a complex heterozygous mutation with the deafness mutation detected by deafness gene screening,leading to the occurrence of congenital deafness.Conclusion Among the four rare deafness mutation sites,8 were heterozygous mutations with c.109G>A,c.257C>G,c.512₅13ins4 and c.313₃26del14 mutation in 1 case each.Through the research of deafness gene database and literature,it is confirmed that these four rare mutation sites are pathogenic,so these 11 patients are GJB2 gene complex heterozygous mutation,which is the main cause of their congenital deafness.