Vitamin D Receptor Polymorphism rs2228570 (Fok1) Is Associated with Rheumatoid Arthritis in North American Natives
The Journal of Rheumatology, 08/02/2012
Hitchon CA et al. – Vitamin D receptor polymorphisms may contribute to the high prevalence of rheumatoid arthritis in North American Native populations.Methods
- The single–nucleotide polymorphism (SNP) Fok1 was tested by sequencing NAN patients with RA (n = 448) and unrelated NAN controls (n = 704).
- Associations were tested using genotypic, dominant, and recessive models.
- The minor allele frequency (F/C) in the NAN control population was 0.44 and lower than reported in white subjects of the same geographical area.
- The Fok1 VitD receptor SNP was significantly associated with RA.
- Comparing patients with RA to unaffected NAN controls, the Fok1 SNP was associated with RA using both genotypic [FF vs Ff vs ff: RA 20%, 54%, 26% vs control 22%, 44%, 34% (chi–square 13.35, p = 0.003)] and dominant models [FF/Ff vs ff: RA 74% vs 26% control 66% vs 34% (OR 1.5, 95% CI 1.16–1.96, p = 0.003)].
- This association was strongest in shared–epitope–positive RA.