Genetic variation in KCNQ4 gene is associated with susceptibility to noise-induced hearing loss in a Chinese population

Noise-induced hearing loss (NIHL), one of the most widespread occupational health risks worldwide, is a kind of complex disorder resulting from both genetic and environmental factors. KCNQ4 channels are crucial to the internal ear potassium recycling. To explore whether KCNQ4 polymorphism is associated with individual susceptibility to NIHL, we performed this genetic association study on 571 NIHL cases and 639 normal hearing controls selected from about 2700 Chinese noise-exposed workers. General information and audiometric data were obtained through questionnaires and pure-tone audiometry (PTA). DNA samples were collected and genotyping for three selected SNPs (rs709688, rs2769256 and rs4660468) was performed. Significant differences were observed between cases and controls for the genotype frequency and allele frequency in rs4660468, suggesting that rs4660468 CT/TT genotype and T allele may be risk factors for NIHL. In subjects exposed to noise for more than 16 years (OR = 1.23, 95% CI = 1.09-1.53) and those who exposed to noise >92 dB (OR = 1.29, 95% CI = 1.08-1.69), increased risks of NIHL were found after stratified analysis for rs4660468. Our results suggest that rs4660468 T allele of KCNQ4 involves with a higher risk of NIHL and could be one biomarker of susceptibility for Chinese noise exposed workers.