Association of PTPN22 (rs2476601) and STAT4 (rs7574865) polymorphisms with rheumatoid arthritis in the Western Algerian population

Abstract

Aim: The aim of the present study was to replicate the association of five risk gene polymorphisms (PTPN22- -rs2476601, STAT4-rs7574865, 6q23-rs6927172, IRF5-rs2004640 and TRAF1/C5-rs10818488) with RA in a specific population of the Western Algeria. Material and methods: The study group comprised 110 patients with RA and 197 ethnically matched heal thy control subjects. All polymorphisms were genotyped using predesigned TaqMan® assays. Allele and genotype frequencies in patients and control subjects were compared by chi-square test and odds ratios with 95% confidence intervals. Correction for multiple testing was carried out using the Bonferroni adjustment. Results: Statistically significant associations with RA were detected. The strongest signal was obtained for PTPN22-rs2476601 with an allelic Pvalue 3.32 x 10 (OR = 9.83, 95% CI [4.28 – 22.56]). A second significant association was obtained with STAT4-rs7574865 (allelic Pvalue = 4x10; OR = 1.75, 95% CI [1.16-2.63]).The third SNP, 6q23-rs6927172, showed a significant result of association with RA, but missed our criteria for significance at allelic level after Bonferroni’s correction (allelic Pvalue =0.027; OR =0.64,95% CI [0.42– 0.97]). Finally, IRF5-rs2004640 and TRAF1/C5-rs10818488 showed a significant association only at genotypic level (Pvalues: 3x10-3 and 2.9 x10-3-4 respectively) but did not reach statistical significance when comparing allele frequencies (Pvalues: 0.96 and 0.21 respectively). Conclusions: From this initial study, we can conclude that PTPN22-rs2476601 and STAT4-rs7574865 poly- -11 morphisms are clearly associated with the risk of RA in the Western Algerian population.