X-Ray Repair Cross-Complementing Group 1 Genetic Polymorphisms and the Risk of Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSNHL) is a condition with largely unknown etiology, though both vascular and genetic components have been implicated. The X-ray repair cross-complementing group 1 (XRCC1) gene, involved in DNA repair and oxidative stress response, has been linked to ischemic stroke and noise-induced hearing loss. This study aimed to investigate the association between XRCC1 single nucleotide polymorphisms (SNPs) and SSNHL risk in Taiwan.

Prospective case-control study.

Tertiary academic medical center.

A total of 276 patients with SSNHL and 293 healthy controls were enrolled. Three XRCC1 SNPs (rs1799782, rs25489, and rs25487) were genotyped using TaqMan assays. All SNPs were tested for Hardy-Weinberg equilibrium. Associations with SSNHL risk were analyzed under dominant and recessive models using multivariate logistic regression. Clinical predictors of recovery were also evaluated.

The TT genotype of XRCC1 rs1799782 was significantly associated with increased SSNHL risk compared with the CC genotype [adjusted odds ratio (aOR)=2.005; 95% CI=1.13-3.62; P =0.0164]. This association persisted under the recessive model (TT vs. CC+CT) (aOR=1.983; 95% CI=1.15-3.49; P =0.0134). No significant associations were observed for rs25489 and rs25487. High-tone (aOR=6.42; P = 0.0043) and flat-type (aOR=4.12; P =0.0071) audiogram patterns and longer treatment delay were linked to unfavorable clinical outcomes. XRCC1 genotypes were not predictive of treatment response.

The TT genotype of XRCC1 rs1799782 is significantly associated with increased SSNHL susceptibility in the Taiwanese population.