A single nucleotide polymorphism rs9468925 of MHC region is associated with clinical features of generalized vitiligo in Chinese Han population

Background Vitiligo has been found to be associated with different HLA antigens in different ethnic groups. In our previous genome‐wide association study (GWAS), we identified independent association signal of rs9468925 (P = 2.21 × 10^?33, OR = 0.74) within HLA‐C‐HLA‐B region. Objectives To explore the association between rs9468925 polymorphism within MHC and the clinical features of generalized vitiligo. Methods The study, using 5566 cases and 6462 controls from previous GWA study investigated the single and combined (GA + GG) genotypic distribution of rs9468925 in subsets of vitiligo patients having different clinical features. We performed a QTL analysis (quantitative trait locus) for age of onset with genotype of rs9468925. Results The GA + GG genotypic distribution of SNP rs9468925 tested with an additive model was found to be significantly different in subgroups of patients of >20 vs. <20 years old (genotypic P = 2.57 × 10^?4, combined P = 3.0 × 10^?3, OR = 0.77, 95% CI: 0.64–0.92), and in patients with different clinical subtypes of vitiligo (genotypic P = 0.03, combined P = 5.0 × 10^?3). However, there was no statistical significance for familial history, halo nevi involvement and autoimmune disease involvement. Conclusions Allele G of rs9468925 on HLA‐C‐HLA‐B may be associated with a higher risk of vitiligo. Our study showed a significant genotypic variation between patients with age of onset ≤20 years and age of onset >20 years. Obvious clinical differences of generalized vitiligo related to genotypic variation found in the Chinese Han population were confirmed in this study.