Multi-ancestry genome-wide association analyses identify 124 risk loci for rheumatoid arthritis, of which 34 are novel. A polygenic risk score based on multi-ancestry data showed comparable... Show moreMulti-ancestry genome-wide association analyses identify 124 risk loci for rheumatoid arthritis, of which 34 are novel. A polygenic risk score based on multi-ancestry data showed comparable performance between populations of European and East Asian ancestries.Rheumatoid arthritis (RA) is a highly heritable complex disease with unknown etiology. Multi-ancestry genetic research of RA promises to improve power to detect genetic signals, fine-mapping resolution and performances of polygenic risk scores (PRS). Here, we present a large-scale genome-wide association study (GWAS) of RA, which includes 276,020 samples from five ancestral groups. We conducted a multi-ancestry meta-analysis and identified 124 loci (P < 5 x 10(-8)), of which 34 are novel. Candidate genes at the novel loci suggest essential roles of the immune system (for example, TNIP2 and TNFRSF11A) and joint tissues (for example, WISP1) in RA etiology. Multi-ancestry fine-mapping identified putatively causal variants with biological insights (for example, LEF1). Moreover, PRS based on multi-ancestry GWAS outperformed PRS based on single-ancestry GWAS and had comparable performance between populations of European and East Asian ancestries. Our study provides several insights into the etiology of RA and improves the genetic predictability of RA. Show less
Isobe, Y.; Ouchi, M.; Suzuki, A.; Moriya, T.J.; Nakajima, K.; Nomoto, K.; ... ; Xu, Y. 2022
Objective To elucidate the differential role of peptidyl arginine deiminase 4 (PADI4) polymorphism in rheumatoid arthritis (RA) between Asian and European populations, possible gene-environmental... Show moreObjective To elucidate the differential role of peptidyl arginine deiminase 4 (PADI4) polymorphism in rheumatoid arthritis (RA) between Asian and European populations, possible gene-environmental interactions among the PADI4 polymorphism, sex and smoking status were analysed. Methods Three independent sets of case-control samples were genotyped for single-nucleotide polymorphisms in PADI4; Japanese samples (first set, 1019 RA patients, 907 controls; second set, 999 RA patients, 1128 controls) using TaqMan assays and Dutch samples (635 RA patients, 391 controls) using Sequenom MassARRAY platform. The association of PADI4 with RA susceptibility was evaluated by smoking status and sex in contingency tables and logistic regression models. Results In the first set of Japanese samples, PADI4 polymorphism (rs1748033) showed a greater risk in men (ORallele 1.39; 95% CI 1.10 to 1.76; p(trend) = 0.0054) than in women and in ever-smokers (ORallele 1.25; 95% CI 1.02 to 1.53; p(trend) = 0.032) than in never-smokers. Moreover, the highest risk was seen in male ever-smokers (ORallele 1.46; 95% CI 1.12 to 1.90; p(trend) = 0.0047). Similar trends were observed in the second set of Japanese samples as well as in Dutch samples. Conclusion PADI4 polymorphism highly predisposes male smokers to RA, and the genetic heterogeneity observed between Asian and European populations may be partly explained by differences in smoking prevalence among men. Show less
