MTHFR and rheumatoid arthritis: While no statistically significant differences between the groups were detected for the MTHFR C677T, the CC genotype of the MTHFR A1298Cvariant was more frequent among RA patients (adjustment for age and gender in the recessive model genotype CC vsAA/AC: OR [95% CI] 1.77 [1.05–2.98], p-value: 0.031).