Carrier frequencies, trends, and geographical distribution of hearing loss variants in China: The pooled analysis of 2,161,984 newborns

ObjectiveThe aim of this study is to comprehensively investigate the prevalence and distribution patterns of three common genetic variants associated with hearing loss (HL) in Chinese neonatal population. Methods: Prior to June 30, 2023, an extensive search and screening process was conducted across multiple literature databases. R software was utilized for conducting meta-analyses, cartography, and correlation analyses. Results: Firstly, our study identified a total of 99 studies meeting the inclusion criteria. Notably, provinces such as Qinghai, Tibet, Jilin, and Heilongjiang lack large-scale genetic screening data for neonatal deafness. Secondly, in Chinese newborns, the carrier frequencies of GJB2 variants (c.235delC, c.299_300delAT) were 1.63 % (95%CI 1.52 %–1.76 %) and 0.33 % (95%CI 0.30 %–0.37 %); While SLC26A4 variants (c.919-2A > G, c.2168A > G) exhibited carrier rates of 0.95 % (95%CI 0.86 %–1.04 %) and 0.17 % (95%CI 0.15 %–0.19 %); Additionally, Mt 12S rRNA m.1555 A > G variant was found at a rate of 0.24 % (95 % CI 0.22 %–0.26 %). Thirdly, the mutation rate of GJB2 c.235delC was higher in the east of the Heihe-Tengchong line, whereas the mutation rate of Mt 12S rRNA m.1555 A > G variant exhibited the opposite pattern. Forthly, no significant correlation exhibited the opposite pattern of GJB2 variants, but there was a notable correlation among SLC26A4 variants. Lastly, strong regional distribution correlations were evident between mutation sites from different genes, particularly between SLC26A4 (c.919-2A > G and c.2168A > G) and GJB c.299_300delAT. Conclusions: The most prevalent deafness genes among Chinese neonates were GJB2 c.235delC variant, followed by SLC26A4 c.919-2A > G variant. These gene mutation rates exhibit significant regional distribution characteristics. Consequently, it is imperative to enhance genetic screening efforts to reduce the incidence of deafness in high-risk areas.