Genetic Variants of the Receptor Activator Nuclear of κB Ligand Gene Increase the Risk of Rheumatoid Arthritis in a Mexican Mestizo Population: A Case-Control Study.

Unlabelled: The Receptor Activator Nuclear of κB Ligand (RANKL) plays an important function in immune responses, activating osteoclast cells and unchanged bone resorption, which in turn leads to bone erosion and inflammation. Genetic variants in the promoter region of the RANKL gene could lead to a higher risk of rheumatoid arthritis (RA).

Objective: To assess the association of (-693C>G) and (-643T>C) genetic variants with RA risk.

Methods: A case-control study was carried out. A total of 94 patients with RA (RA group) and 134 subjects without any rheumatologic disease (control group) were included. Genetic DNA was extracted from peripheral white blood cells (leukocytes). Genetic variant (-693C>G) was screened by an approach based on Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP), while (-643T>C) was screened using quantitative polymerase chain reaction (qPCR) with TaqMan probes. RANKL serum levels were measured by ELISA.

Results: For (-693C>G), the polymorphic homozygous genotype frequencies (CC) were higher in the RA group ( = 0.006). Individuals carrying the risk genotype presented higher levels of serum RANKL. Carriers of the polymorphic homozygous genotype in the dominant model (CC vs. CG + GG) had an increased risk of developing RA (OR: 1.8, 95% CI 1.04 to 3.1). No association between (-643T>C) and the haplotypes with RA risk was observed.

Conclusion: The (-693C>G) genetic variant exhibits a potential role in RA risk. The studied population had no association with the (-643T>C) genetic variant.