Objective: To explore the characteristics of mutations of four common pathogenic genes (GJB2, SLC26A4, GJB3 and 12S rRNA) among patients with nonsyndromic hearing loss (NSHL) from eastern Shandong.
Methods: Peripheral blood samples of 420 NSHL patients were collected, and a hereditary-deafness-gene microarray was used to detect GJB2 c.235delC, c.299-300delAT, c.35delG and c.176del16 mutations, GJB3 c.538C>T mutation, SLC26A4 c.2168A>G and c.IVS7-2A>G mutations, and 12S rRNA c.1555A>C and c.1494C>T mutations. For patients carrying single heterozygous mutations, the coding regions of the above genes were analyzed with Sanger sequencing.
Results: The results of the microarray assay and Sanger sequencing showed that 84 patients (20.00%) carried GJB2 mutations, with c.235delC (16.43%) and c.299-300delAT (7.86%) being most common. Seventy-five patients (17.86%) carried SLC26A4 mutations, for which c.IVS7-2A>G accounted for 15.71%. In addition, 5.95% of patients carried 12S rRNA mutations. Only one patient was found to carried GJB3 mutation (c.538C>T).
Conclusion: Common pathogenic mutations for NSHL in eastern Shandong included GJB2 c.235delC and SLC26A4 c.IVS7-2A>G. Of note, 5.95% of patients were due to 12S rRNA m.1555A>G mutation, which gave a frequency greater than other regions of China.