ATIC and rheumatoid arthritis: Regarding the comparison of variants between the study groups, the ATIC gene rs3821353 G variant was more frequent among RA patients (G allele: 72% in RA patients versus 57% in the control group, p = 0.001), and for ATIC gene rs4673990, variant G was more frequent among RA patients (G allele: 39% in RA patients versus 24% in the control group, p < 0.001).