The Association of Vitamin D Receptor Polymorphisms of FokI and TaqI with Rheumatoid Arthritis in North-East of Iran

Vitamin D receptor (VDR) has been identified as a susceptibility gene for several autoimmune diseases. This study was designed to investigate the association of VDR gene polymorphisms with the susceptibility to rheumatoid arthritis (RA).

A case-control study was performed on 130 RA patients and 128 healthy subjects in the north-east of Iran using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) technique.  

Our findings suggested a significant association of T allele (p=0.01) of TaqI (rs731236), and f allele (p=0.01) of FokI (rs10735810) genetic variants of the VDR gene with RA susceptibility. These significant associations were also found in the T/T genotype of TaqI (p=0.009), and F/f genotype of FokI (P=0.014). The f-T haplotype was more significantly detected in-patients than in healthy controls (p=0.007).

The RA group showed an increase in the f allele and heterozygous F/f genotype and also in the T allele and homozygous T/T and heterozygous T/t genotypes as compared to the control group. Our results demonstrated that polymorphisms of TaqI and FokI in the VDR gene might be involved in the development of RA in an Iranian population.