Impact of MTHFR rs1801133, MTHFR rs1801131 and ABCB1 rs1045642 polymorphisms with increased susceptibility of rheumatoid arthritis in the West Algerian population: A case-control study.

Rheumatoid arthritis (RA) is an autoimmune disease that results in a chronic systemic inflammation. A few genetic epidemiologic studies found a potential association between genetic polymorphisms C677T (rs1801133) and A1298C (rs1801131) of methylenetatrahydrofolate reductase (MTHFR) gene and C3435T (rs1045642) of ATP-Binding cassette (ABCB1) gene and the increased risk for RA. The aim of this case-control study was to determine the relationship between these polymorphisms and RA susceptibility in West Algerian population. The dataset of the current study is composed of 110 RA patients and 101 healthy controls. All samples were genotyped for theses polymorphisms by TaqMan® allelic discrimination assay. Data were compared between cases and controls by the calculation of the odds ratio (OR) with a confidence interval at 95%. After age and RA erosion-stratified analyzes, no differences in genotypes or alleles frequencies distribution were found for MTHFR C677T (rs1801133) and ABCB1 C3435T (rs1045642) polymorphisms between RA cases and controls. However, the MTHFR A1298C (rs1801131) polymorphism presented a significant distribution in RA with age ≥ 40 (Genotypic data: p=0.007, OR=13.53[1.44-63.31], Allelic data: p=0.001, OR=2.39[1.39-4.1]), and in RA erosive form (Genotypic data: p=0.002, OR=6.92[1.68-30.23], Allelic data: p=0.0001, OR=2.43[1.54-3.85]).These results were confirmed after the Bonferroni correction. In this study we have showed, for the first time in the West Algerian population, that the MTHFR A1298C (rs1801131) polymorphism can be associated with rheumatoid arthritis.