Association of interferons regulatory factor 5 gene polymorphisms with rheumatoid arthritis in shaanxi Han Chinese population

Objective Previous studies have shown that genetic variants in the interferons regulatory factor 5(IRF5) gene are associated with rheumatoid arthritis(RA) in European and Japanese, but not found in Han Chinese. We conducted this study to investigate whether genetic variants in the IRF5 gene are associated with RA in ShaanXi Han Chinese population. Methods This study was collected 576 RA patients and 768 normal controls. Six IRF5 gene polymorphisms (rs729302, rs2004640, rs752637, rs3807306, rs10954213 and rs2280714) were genotyped by the SNaPshot method. T-test and χ2 test were used for statistic analysis. The genotype and allele frequencies were evaluated using the chi square tests. Genotyping data were adjusted by Logistic regression method by age and gender. The linkage disequilibrium (LD) block structure was examined using Hapview 4.2 software. Results Six SNPs inspected complied with Hardy-weinberg equilibrium (P>0.05). Two SNPs were significantly associated with RA: rs729302 A risk allele [OR=1.29, 95% CI (1.10, 1.50), P=5.57 × 10-3]; dominant model [OR=1.58, 95% CI (1.10, 2.27), P=0.024], recessive model [OR=1.31, 95% CI (1.17, 1.64), P=0.028]. rs2004640 T risk allele [OR=1.28, 95%CI (1.08, 1.54), P=0.039]; dominant model [OR= 1.27, 95% CI (1.03, 1.58), P=0.036]. In addition, there was no significant difference in rs752637, rs3807306, rs10954213 and rs2280714 SNPs between RA group and control and genotyped polymorphisms were significantly associated with RA susceptibility. Conclusion The present study confirm that rs729302 and rs2004640 in the IRF5 gene is significantly associated with increased risk of RA in ShaanXi Han Chinese population. Key words: Arthritis, rheumatoid; Polymorphism, single nucleotide; Interferons regulatory factor 5