Whole-exome sequencing identifies genetic variants of hearing loss in 113 Chinese families

Background: Hearing loss is a group of diseases with high genetic heterogeneity. About 160 genes have been reported to be associated with hereditary hearing loss.Methods: 113 families with hearing loss were collected, and WES was used to detect SNV, InDel, CNV and mitochondrial gene variants. For some probands with negative WES test results, the copy number of STRC and OTOA were determined by using real-time fluorescence quantitative PCR.Results: Pathogenic or likely pathogenic variants were found in 54 probands, of which 98% (53/54) were SNVs or InDels and 2% (1/54) were CNVs, a positive rate of 48%. 16 families (14%) were detected with candidate variants of uncertain significance. 19 novel pathogenic or likely pathogenic variants and 22 candidate variants of uncertain significance were identified in this study. The most common hearing loss gene in the families was GJB2, accounting for 28% (15/53), followed by SLC26A4 and MYO15A, accounting for 21% (11/53) and 11% (6/53), respectively. Heterozygous gene deletion was detected in 3 probands, including 2 with STRC and 1 with OTOA in 43 families with WES negative test.Conclusion: Genetic etiology was clarified in 54 families. All of these findings broadened the mutation spectrum of hearing loss genes, thus providing new variant information for the future diagnosis of patients with hearing loss.