While non-synonymous rs33996649 (R263Q) did not pass the threshold for significance, the P-value was suggestive (P = 0.08) in EA. This SNP, which lies within the catalytic domain of enzyme, is correlated with PTPN22 gene expression [60], leads to reduced phosphatase activity [61] and was negatively associated with SLE in Europeans [61]. An association independent of rs2476601 was identified for rs1217414 and rheumatoid arthritis in populations of European and Asian descent. Our data does not support a significant association of this SNP with SLE in non-European derived populations (Table S1).
