Vitamin D receptor polymorphisms among the Turkish population are associated with multiple sclerosis

Abstract

Multiple sclerosis (MS) is an inflammatory disease characterized by demyelination and axonal degeneration affecting the central nervous system. Among the genetic factors suggested to be associated with this disease are polymorphisms to the vitamin D receptor (VDR) gene. We tested the hypothesis that polymorphisms in the vitamin D receptor (VDR) gene are associated with MS. The aim of the study was to investigate the relationship of MS with the VDR gene Fok-I, Bsm-I and Taq-I polymorphisms among the Turkish population. This study contains 271 MS patients and 203 healthy controls. Genomic DNA was isolated from the samples and the VDR gene Fok-I, Bsm-I and Taq-I polymorphism regions were amplified by polymerase chain reaction (PCR). The PCR products were digested, and the genotypes were determined based on size of digested PCR products. Our results demonstrate associations between MS and the distribution of the VDR gene Fok-I T/T polymorphism genotype in a dominant model, VDR gene Fok-I T allele frequency, distribution of VDR gene Taq-I C/C polymorphism genotype in a dominant model and VDR gene Taq-I C allele frequency (Pearson test, p<0.05). However, there was no association between MS and the VDR gene Bsm-I polymorphisms for the genotype distribution (Pearson test, p>0.05) or allele frequency (Pearson test, p>0.05). Fok-I and Taq-I VDR gene polymorphisms are significantly associated with MS in dominant, homozygote and heterozygote inheritance models among the Turkish population.