Confirmation of association of the REL locus with rheumatoid arthritis susceptibility in the UK population

Genome-wide association studies (GWAS) have contributed to the identification of at least 14 rheumatoid arthritis (RA) susceptibility loci.1 One of the first RA GWAS included 1522 cases and 1850 controls from the USA/Sweden and identified TRAF1/C5 as a novel RA locus.2 This GWAS was recently repeated after including an additional 1550 cases and 3310 controls from the USA and restricting analysis to US subjects.3 In the expanded sample, two novel single nucleotide polymorphisms (SNP) mapping to the REL locus showed association with RA. REL encodes c-Rel, a member of the nuclear factor kappa B family of transcription factors and one of the associated SNP (rs13031237) maps to an intron of this gene. The association was validated in an independent sample of 2604 RA cases and 2882 controls from the USA/Canada, with strong evidence for association in the combined samples (rs13031237, p=3.1×10−14). We aimed to test the …