Genetic variant and vitamin D in multiple sclerosis: Association of the BsmI (rs1544410) Polymorphism in a western Mexican population.

BACKGROUND

Multiple Sclerosis (MS) is a multifactorial disease; result of an interaction among environmental and genetic factors, among vitamin D hypovitaminosis. Genetic variants in vitamin D receptor (VDR) may affect vitamin D functionality and levels, increasing the susceptibility to MS risk.

OBJECTIVE

To identify the association between the BsmI (rs1544410) polymorphism of the VDR gene, using dominant, recessive, co-dominant, and the risk of MS in a western Mexican population.

METHODS

A case-control study was performed. One hundred and seventy-five patients with MS and 118 controls were genotyped for the BsmI VDR gene polymorphism using qPCR. Dominant, recessive, co-dominant, were analyzed. Serum vitamin D levels were measured by ELISA. A case-control study was performed. One hundred and seventy-five patients with MS were included and one hundred and eighteen subjects in the control group. Genomic DNA was extracted from peripheral blood leukocytes. Genetic variants for BsmI VDR gene were analyzed by quantitative polymerase chain reaction (qPCR) using TaqMan probes and serum vitamin D levels were quantified by enzyme-linked immunosorbent assay.

RESULTS

Vitamin D levels were lower (Median: 16.4 ng/mL vs. 29.1 ng/mL, p < 0.001) in MS vs. the control group. Multiple Sclerosis patients with azathioprine (Imuran) rituximab had sufficient levels, and with rituximab a tendency of sufficient levels of vitamin D. Carriers of allele G had a 1.4-fold increase in the risk of MS (OR: 1.4, 95 % CI; 1.01 - 2.14, p = 0.06). Subgroup analyses revealed no statistically significant interactions between genotype and sex, age, smoking, alcohol consumption, or vitamin D status, although tobacco use showed a near-significant association in the dominant model (OR = 2.4, 95 % CI: 0.94-6.50).

CONCLUSION

No association was observed between the VDR genetic variant for BsmI and MS risk in a western Mexican population. Carries of allele G increase the risk of MS. Large studies should be performed to further validate these findings.