Association of single nucleotide polymorphisms in the IL2RA-RBM17 region with vitiligo in the Chinese Mongolian population

Abstract

Objective To investigate the association between single nucleotide polymorphisms(SNPs)in the IL2RA-RBM17 region and vitiligo in the Chinese Mongolian population. Methods Five milliliters of venous blood samples were collected from 425 patients with vitiligo(patient group)and 503 healthy human controls(control group)of Mongolian nationality after informed consent, and genomic DNA was extracted with the AxyPrep DNA extraction kit(AP-MX-BL-GDNA-25). Nine SNPs were selected across the IL2RA-RBM17 region, including rs706779, rs3134883, rs7090530, rs12251307, rs4750005, rs3920615, rs4747887, rs4750012 and rs7099083. Ligase detection reaction(LDR)was performed for SNP genotyping. With the PLINK 1.07 and SPSS 11.0 packages, statistical analysis was carried out by the chi-square test for comparisons of allele and genotype frequencies between the patient group and control group. Linkage disequilibrium analysis was performed for 5 SNPs by calculating the r2 and D' values. Haplotype analysis of 5 related SNPs was conducted to investigate differences in haplotype frequencies between the patient group and control group. Results There were significant differences in allele frequencies of 5 SNPs, including rs4750005, rs3920615, rs4747887, rs4750012 and rs7099083, between the patient group and control group(all P < 0.05). Under a dominant mode of inheritance, a significant decrease was observed in the frequencies of GG/GC genotypes of rs3920615, CT/CC genotypes of rs4747887, CT/CC genotypes of rs4750005, TC/TT genotypes of rs4750012 and AG/AA genotypes of rs7099083 in the patient group compared with the control group(all P < 0.005 6). Moderate to strong linkage disequilibrium was observed between the 5 SNPs(D' = 0.424-1, r2 = 0.137-0.985). Haplotype analysis showed that the frequency of a haplotype(H2: CGCTA)was significantly lower in the patient group than in the control group, and the difference reached statistical significance after Bonferroni adjustment(P= 0.001 6, OR = 0.674). Conclusion SNPs in the IL2RA-RBM17 region are associated with vitiligo in the Chinese Mongolian population. Key words: Vitiligo; Polymorphism, single nucleotide; Mongolia; Genetic association studies; Genes, IL2RA-RBM17; China