Background Previous genome wide association studies (GWASs) have demonstrated the association between IL-10 region and Behcet’s disease (BD) in Turkish and Japanese populations. However, our recent GWAS result obtained from a Korean population  did not replicate this finding, suggesting a significant ethnic difference in genetic susceptibility for BD.
Objectives To fully examine the relationship between IL-10 and BD, the associations between BD and single nucleotide polymorphisms (SNPs) in IL-10 mediated signaling pathways were examined in Korean BD patients.
Methods DNA samples were obtained from 181 patients who met the international study group criteria for BD and 181 age- and sex-matched healthy controls. Eighteen tag SNPs in JAK1 (rs17127024, rs310245, rs2991269, rs2230587, rs2780898, rs2274948, rs310222, rs2256298, rs3818753, rs2780831, rs10889502, rs12563017, rs11208537, rs11208538, rs1353595, rs17127171, rs7553101, and rs4244165), five in TYK2 (rs34536443, rs12720356, rs2304256, rs280523, and rs12720217), and five in STAT3 (rs3744483, rs2293152, rs6503695, rs744166, and rs12948909) selected using the Japanese panel of international HapMap data with a minor allele frequency of more than 5% and with r2 > 0.8 were genotyped using PCR and RFLP method.
Results The mean (± standard deviation) age of BD patients was 43.4 ± 10.3 years. Eighty five (47.0%) patients were male. The mean age and gender distribution of controls were similar. Genetic loci with a deviation from Hardy-Weinberg equilibrium in controls (rs11208538 in JAK1), or without any polymorphism in study subjects (rs34536443 and rs12720356 in TYK2) were not included in the analysis. The frequency of C allele at rs12948909 in STAT3 was higher in BD patients than in controls (odds ratio = 1.54, 95% confidence interval [1.00-2.38], p = 0.047), which, however, lost statistical significance after permutation-based correction for multiple testing. No significant associations were found between alleles of the rest 24 SNPs and BD. In addition, there was no genotype found to have a significant association with BD. In linkage disequilibrium (LD) analysis, eight haplotypes from two LD blocks in JAK1 and three haplotype from one LD block in STAT3 were identified but showed no association with BD.
Conclusions Together with our GWAS finding, the result of this study further suggests that genetic dysregulation of IL-10 or IL-10 mediated intracellular signaling is not a predominant pathogenic mechanism for BD in Koreans.
Lee YJ, Horie Y, Wallace GR, Choi YS, Park JA, Song R, Kang YM, Kang SW, Baek HJ, Kitaichi N, Meguro A, Mizuki N, Namba K, Ishida S, Kim J, Niemczek E, Lee EY, Song YW, Ohno S, Lee EB. Genome-wide association study identifies GIMAP as a novel susceptibility locus for Behcet’s disease. Ann Rheum Dis. 2012 Oct 6. [Epub ahead of print]
Disclosure of Interest None Declared