The association between multiple sclerosis and genetic variations of TGFβ1 and IL2 genes in Iraqi patients

Abstract

The aim of current study is to highlight the association between predisposition to multiple sclerosis (MS) and single nucleotide polymorphisms (SNPs) of interleukin-2 (IL2−330 and IL2+166) and transforming growth factor-beta (TGFβ1+869 and TGFβ1+915) genes. A total of 68 Iraqi Arab MS patients and 158 age-gender-ethnicity matched healthy subjects were enrolled in this study to determine the genotypes / alleles of IL2−330, IL2+166, TGFβ1+869 and TGFβ1+915 SNPs using sequence-specific primer polymerase chain reaction (SSP-PCR). Significant increased frequencies of GG genotype and G allele of IL2+166 SNP was observed in MS patients as compared to controls (77.9% vs. 31.7%, P = .000, OR = 7.6; 85% vs. 60%, P = .00, OR = 3.7, respectively). The frequency of TGFβ1+915 SNP GG genotype and G allele were also significantly higher in patients than in controls (72.1% vs. 48.7%, P = .002, OR = 2.7; 85% vs. 70%, P = .001, OR = 2.4, respectively). There was a complete linkage disequilibrium (LD) between −330 and + 166 SNPs of IL2, whereas LD was absent from TGFβ1 SNPs in MS patients. Additionally, TG haplotype of IL2–330,+166 and CG haplotype of TGFβ1+869, +915 showed a significant increased distribution in patients rather than in controls (37.2% vs. 21.8%, P = .000, OR = 2.2; 46.3 vs. 33.1%, P = .008, OR = 1.7, respectively). Consequently, GG genotype / G alleles and TG haplotype of IL2–330,+166 and GG genotype / G alleles and CG haplotype TGFβ1+869, +915 may comprise risk factors for susceptibility to MS in this sample of Iraqi population.