The Genetic Association of rs5746105 Polymorphism of SOD2 with the Susceptibility to Sudden Deafness.

BACKGROUND

Sudden deafness (SD) is defined as unexplained hearing loss of at least 30 decibels (dB) occurring within 72 hours over at least 3 contiguous frequencies, with idiopathic etiology that may be influenced by genetic factors. This study aimed to investigate the association between the rs5746105 polymorphism of the superoxide dismutase 2 (SOD2) gene and SD.

METHODS

In this study, 150 patients diagnosed with SD were consecutively recruited and 150 healthy individuals were selected as controls. The genotyping of the SOD2 rs5746105 polymorphism was performed using the PCR-RFLP method. The Hardy-Weinberg equilibrium test was applied to evaluate the distribution of gene and genotype frequencies. Logistic regression analysis was conducted to identify potential independent risk factors for SD.

RESULTS

Smoking, hypertension, diabetes, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) were significantly associated with the onset of SD (P < .05). The SOD2 rs5746105 gene polymorphism was also linked to SD. Specifically, the A allele (P = .017, OR = 1.485, 95% CI: 1.073-2.055) and the GA/AA genotypes (P = .015, OR =2.149, 95% CI: 1.152-4.009) were associated with an increased risk of SD. In patients with SD and mild hearing impairment, the AA genotype (P = .029, OR = 2.473, 95% CI: 1.164-5.249) may be a significant risk factor. Logistic regression analysis identified smoking, hypertension, and the rs5746105 polymorphism as independent risk factors for SD (P < .05).

CONCLUSION

The rs5746105 polymorphism in the SOD2 gene was associated with an increased susceptibility to SD.