Analysis of Polymorphisms Associated with Base Excision Repair in Patients Susceptible and Resistant to Noise-Induced Hearing Loss

OBJECTIVE: Noise-induced hearing loss (NIHL) is one of the most common occupational health risks in both developed and industrialized countries. It occurs as a result of interactions between genetic and environmental factors. Nevertheless, inherited genetic factors contributing to NIHL are not well understood. Therefore, we aim to investigate whether genetic mutations in three important base excision repair genes (OGG1, APEX1, and XRCC1) may influence susceptibility to NIHL. METHODS: Three SNPs in OGG1, APEX1, and XRCC1 were genotyped from 1170 noise-exposed workers and were classified into 117 most susceptible and 117 most resistant individuals. RESULTS: Results showed that the rs1799782 TT genotype located in the XRCC1 coding region and rs1130409 GG/GT in the APEX1 coding region were associated with increased risk for NIHL in a Chinese population. Compared to the rs1799782 C allele frequency, the T allele frequency was increased in the sensitive group (adjusted OR = 1.51, 95%CI = 1.01 to 2.26, P = 0.043). The rs1130409 G allele frequency was also increased in the sensitive group compared to the resistant group (adjusted OR = 1.59, 95%CI = 1.10 to 2.31, P = 0.015). Moreover, rs1130409 and drinking had a statistically significant interaction (P = 0.0002), while rs1799782, rs1130409, and smoking also had a statistically significant interaction (P < 0.0001). CONCLUSIONS: XRCC1 rs1799782 and APEX1 rs1130409 may have potential as biomarkers for the screening of susceptibility to NIHL in workers exposed severe noise.