GJB2 and SLC26A4 gene mutations in children with non-syndromic hearing loss in Southern China

Non-syndromic hearing loss (NSHL) is a major public health issue and affects a substantial proportion of newborns worldwide. Currently little information is available about the molecular etiology of hearing impairment in the Chinese population. Therefore, this study aimed to perform a comprehensive investigation on the genetic mutation patterns of non-syndromic deafness in Zhongshan City, a city located in Southern China. A total of 112 unrelated school children with NSHL in the Zhongshan city were enrolled in this study. Screening was performed for GJB2, GJB3, SLC26A4 and 12S rRNA using a microarray-based hybridization biochip assay. The incidence of genetic defects in the NSHL children was 38.39% (43/112) in this cohort. Among them, 20.54% of cases were caused by GJB2 mutations (235delC, 299_300delAT and 35delG) and 15.18% of cases had pathogenic mutations in SLC26A4 (IVS7-2A>G and 2168A>G). 0.89% of cases carried mutation in 12S rRNA (1555A>G) and GJB3 mutations (538C>T) were detected in 1.79% of the patients. Our results demonstrated that gene mutations played an important role in the pathogenesis of NSHL in children from the Zhongshan City. GJB2 and SLC26A4 mutations are two major causes contributing to NSHL.