Statistical analysis
Statistical analysis was performed using SPSS 26.0 (International Business Machine Corp, Armonk, NY, USA). The frequencies of genotypes, alleles, and haplotypes between the two groups were analyzed by χ2 or Fisher’s exact methods. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to calculate the risk of susceptibility. The Hardy–Weinberg equilibrium was determined to assess the representativeness of the sample. P < 0.05 was considered statistically significant.