Design And Assessmentof SNP Genotyping Biochip For Hereditary Deafness Gene

With the advancement of the gene mechanism for hereditary deafness,researchers have shifted efforts to genotype-phenotype correlation.In this study,20 mutationhot spots were selected by screening preliminary data in the GJB2 gene,SLC26A4 gene and mtDNA 12 S rRNA gene.A combination of techniques,such as multiple PCR,single base elongation and gene chip,were facilitated to set up the genotyping method for hereditary hearing loss.The designed SNP genotyping microarray was composed of 41 probes in 6 arrays,each of which distributed 144 signal points,and had the ability to detect 6 smaples,the sensitivity of SNP genotyping microarray was 75 pg of genomic DNA per reaction?A set of 23 patient samples confirmed with Sanger sequencing was used for test,the detection specificity was 100%,and false-positive zero;the batch of data analysis was within 10% by the genotyping method for hereditary hearing loss.The expended sample set of 235 patients with non-syndromic hearing impairment were tested further.It was found that,firstly,67 patients carried GJB2 mutated gene,including 34 cases of c.235 delC mutation(14.17%)and 10 cases of c.109G>A mutation(10.21%);secondly,31 patients carried SLC26A4 gene mutation,in which,20 cases of c.919-2A>G(8.51%),and 9 cases of c.2168A>G(3.83%);lastly,21 cases of m.1494C>T(8.94%)and 3 cases m.1555A>G(1.28%)in Mitochondrial DNA 12 S rRNA gene.In conclusion,non-syndromic deafness pathogenic gene in southern China were mainly mutated by GJB2 gene,followed by the mutation of SLC26A4 gene,and finally the mitochondrial DNA 12 S rRNA mutation.