Protective association of VDR gene polymorphisms and haplotypes with multiple sclerosis patients in Egyptian population

Background: Hypovitaminos is D is one of the hazardous factors for multiple sclerosis (MS) and can be attested by expanding clinical studies. We aimed to study vitamin D receptor (VDR) gene polymorphisms: Fokl, Bsml, Apal, Taql, and Tru9l genotype; frequency; haplotype structure; and linkage disequilibrium (LD) in MS Egyptian patients. The study was conducted on 50 MS patients and 50 healthy controls of matching age and sex. Alleles and genotype variants of VDR gene SNPs were analyzed by PCR using the restriction fragment length polymorphism (RFLP). Haplotype and linkage disequilibrium analysis based on the five genetic loci was studied on the detected genotypes. Results: Frequency of Fokl genotype (Ff+ff) was significantly higher in healthy controls (50%) compared to MS (28%) (P = 0.03), and T allele was significantly associated with the control group (OR = 0.42, Cl = 026-0.85, P=0.015). Frequency of Apal genotype (Aa+aa) was significantly higher in MS (60%) (P=0.002), and "a" allele was significantly associated with MS cases (OR = 2.47, Cl = 1.25-4.88, P = 0.008). Taql allelic distribution showed significant association of Y allele with control group (OR = 055, Cl = 031-0.98, P = 0.04). Statistically significant LD was detected between Bsml and Apal in controls and MS {D =0.89 and P < 0.001, and D' = 052 and P < 0.001), respectively. Odd ratios of “fAt" and "BAt" were 02 (95% Q = 0.06-0.66) and 0.43 (95% Cl = 0.19-0.97), respectively, suggesting that MS risk was 5 times and 23 times lesser, respectively, for haplotype carriers compared to non-carriers. Conclusion: The study findings suggest that VDR gene variants "f," "A," and Y alleles as well as VDR gene hapbtypes “BAt" and “fAt" may have a protective effect against MS disease in Egyptian population.