Polymorphism of protein tyrosine phosphatase non-receptor type 22 and protein arginine deiminase 4 gene among Ghanaian rheumatoid arthritis patients: A case-control study.

PAD4 polymorphism was absent, while PTPN22 was present in the Ghanaian population. The association between PTPN22 (rs2476601) and PAD4 (rs2240340) with RA susceptibility could not be established, thus may not contribute as risk factors for RA in the Ghanaian population.