MTHFR and rheumatoid arthritis: We were unable to replicate any of the previously reported associations in patients with rheumatoid arthritis and two functional SNPs in MTHFR and one functional SNP in ATIC. 1,2,4,6,10,11 No associations were detected for carriage of combinations of previously described functionally independent risk alleles in the genes MTHFR (rs1801133 T allele and rs1801131 C allele) and ATIC (rs2372536 G allele).