Exploring Genetic Variability in VDR FokI and BsmI Polymorphisms and Their Association with Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is a chronic, inflammatory autoimmune disease that mainly affects small joints and progresses to larger joints. It impacts approximately 1% of the global population, with women being three times more likely to develop it than men, typically between ages 40 and 50. Genetic and environmental factors, including vitamin D deficiency, contribute to RA development. The vitamin D receptor (VDR) gene plays a crucial role in regulating metabolism and inflammation, making it a key candidate in RA.

This study determines the relationship between VDR FokI (rs10735810) and VDR BsmI (rs1544410) gene polymorphisms in RA patients and healthy controls.

A total of 400 participants were included in the study, consisting of 200 RA patients and 200 healthy controls. Genetic varations of VDR genes was performed using the PCR-RFLP technique.

Among 200 RA patients, 42 (21%) were male and 158 (79%) were female, while in the control group, 40 (20%) were male and 160 (80%) were female. The average age of RA patients was 43±17 years and a mean disease onset at age 30.3±19.3 years. The Ff and ff genotypes of the FokI polymorphism were significantly more frequent in RA patients (OR=1.8, p=0.011 and OR=2.8, p=0.004, respectively). For the BsmI polymorphism, the Bb genotype showed a significant association with RA (OR=1.5, p=0.049), while the bb genotype did not (OR=1.4, p=0.241). Gender-based analysis revealed higher frequencies of the Ff, ff, and bb genotypes in females, with significant associations for Ff (OR=3.0, p=0.009), ff (OR=4.5, p=0.002) for Bsml genotype only bb (OR=3.9, p=0.006) was significantly increase the risk of RA.

This study concluded that the VDR FokI (rs10735810) gene polymorphism was associated with RA, while the VDR BsmI (rs1544410) polymorphism did not appear to have a significant association with the disease.