Meta-analysis identifies nine new loci associated with rheumatoid arthritis in the Japanese population

Yuta Kochi and colleagues report a meta-analysis of genome-wide association studies for rheumatoid arthritis in a Japanese population. They identify nine loci newly associated with rheumatoid arthritis in this population and consider overlap of associations with previous studies in European populations. Rheumatoid arthritis is a common autoimmune disease characterized by chronic inflammation. We report a meta-analysis of genome-wide association studies (GWAS) in a Japanese population including 4,074 individuals with rheumatoid arthritis (cases) and 16,891 controls, followed by a replication in 5,277 rheumatoid arthritis cases and 21,684 controls. Our study identified nine loci newly associated with rheumatoid arthritis at a threshold of P < 5.0 × 10 −8 , including B3GNT2 , ANXA3 , CSF2 , CD83 , NFKBIE , ARID5B , PDE2A - ARAP1 , PLD4 and PTPN2 . ANXA3 was also associated with susceptibility to systemic lupus erythematosus ( P = 0.0040), and B3GNT2 and ARID5B were associated with Graves' disease ( P = 3.5 × 10 −4 and 2.9 × 10 −4 , respectively). We conducted a multi-ancestry comparative analysis with a previous meta-analysis in individuals of European descent (5,539 rheumatoid arthritis cases and 20,169 controls). This provided evidence of shared genetic risks of rheumatoid arthritis between the populations.