Identification of a 3′-Untranslated Genetic Variant of RARB Associated With Carotid Intima-Media Thickness in Rheumatoid Arthritis: A Genome-Wide Association Study

Objective To investigate the genetic background influencing the development of cardiovascular (CV) disease in patients with rheumatoid arthritis (RA). Methods We performed a genome-wide association study (GWAS) in which, after quality control and imputation, a total of 6,308,944 polymorphisms across the whole genome were analyzed in 2,989 RA patients of European origin. Data on subclinical atherosclerosis, obtained through assessment of carotid intima-media thickness (CIMT) and presence/absence of carotid plaques by carotid ultrasonography, were available for 1,355 individuals. Results A genetic variant of the RARB gene (rs116199914) was associated with CIMT values at the genome-wide level of significance (minor allele [G] beta coefficient 0.142, P = 1.86 x 10(-8)). Interestingly, rs116199914 overlapped with regulatory elements in tissues related to CV pathophysiology and immune cells. In addition, biologic pathway enrichment and predictive protein-protein relationship analyses, including suggestive GWAS signals of potential relevance, revealed a functional enrichment of the collagen biosynthesis network related to the presence/absence of carotid plaques (Gene Ontology no. 0032964; false discovery rate-adjusted P = 4.01 x 10(-3)). Furthermore, our data suggest potential influences of the previously described candidate CV risk loci NFKB1, MSRA, and ZC3HC1 (P = 8.12 x 10(-4), P = 5.94 x 10(-4), and P = 2.46 x 10(-4), respectively). Conclusion The present findings strongly suggest that genetic variation within RARB contributes to the development of subclinical atherosclerosis in patients with RA.