Mutations of GJB2,SLC26A4,and mitochondrial DNA 12S rRNA in Children with non-syndromic hearing loss in Hubei Province of China

Objective To examine the mutation frequencies of deafness genes GJB2,SLC26A4,and mitochondrial DNA(mtDNA)12SrRNA in children associated with non-syndromic hearing loss,and to expand data base of mutation in Chinese,for development of optimal genetic screening services for hearing impairment. Methods Blood samples and clinical data of 220 sporadic cases with non-syndromic hearing loss and 150 normal controls were collected.The GJB2,SLC26A4,and mtDNA 12 SrRNA gene of the patients and normal controls were amplified by polymerase chain reaction(PCR),then subjected to automatic DNA sequencing. Results Analysis revealed that 146(66.36%)and 35(15.91%)of 220 patients with hearing loss carried at least 1mutant allele in GJB2 and SLC26A4respectively,and 3(1.36%)patients carried mtDNA A1555 Gmutations.Overall 36 mutations were detected in this cohort of patients,including 2novel mutations in GJB2 and 1novel mutation in SLC26A4 respectively.GJB2gene c.235delC(19.32%)and SLC26A4 gene IVS7-2AG(9.09%)were the most common pathogenic mutation.3(2%)of 150 normal control carried pathogenic mutations in GJB2 gene. Conclusion This research demonstrated that a high prevalence of GJB2,SLC26A4,and mtDNA A1555 Gmutations in Chinese children with non-syndromic hearing loss,and expanded data base of common gene of deafness,and discovered 3novel mutations,which provided basic information for the molecular diagnosis and gene screening of deafness.