title: A single nucleotide polymorphism rs9468925 of MHC region is associated with clinical features of generalized vitiligo in Chinese Han population.
abstract: 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.
  
  
  OBJECTIVE
  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.
authors.affiliation: Department of Dermatology at No 1 Hospital, Institute of Dermatology, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Jianlan
authors.initials: J
authors.lastname: Liu
authors.forename: HuaYang
authors.initials: H
authors.lastname: Tang
authors.forename: XianBo
authors.initials: X
authors.lastname: Zuo
authors.forename: Bo
authors.initials: B
authors.lastname: Liang
authors.forename: PeiGuang
authors.initials: P
authors.lastname: Wang
authors.forename: LiangDan
authors.initials: L
authors.lastname: Sun
authors.forename: Sen
authors.initials: S
authors.lastname: Yang
authors.forename: XueJun
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002681:China; D005006:Ethnicity / Q000235:genetics*; D005260:Female; D055106:Genome-Wide Association Study; D006801:Humans; D007223:Infant; D008285:Major Histocompatibility Complex / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D014820:Vitiligo / Q000235:genetics*; D055815:Young Adult