Analysis of linkage and association of alleles of proinflammatory cytokines genes IL-6, IFNg and TNF with multiple sclerosis using transmission disequilibrium test (TDT)

Proinflammatory cytokines Interleukin-6 (IL-6), Interferon-gamma (IFNg) and Tumor necrosis factor (TNF) are known as participants of inflammation and play an important role in pathogenesis of multiple sclerosis (MS). Based on literature data about influence of SNPs G(-308)A of TNF gene, A(+874)T of IFNG gene and G(-174)C of IL-6 gene on production of these cytokines, we investigated association of these polymorphic sites with MS. Linkage and association of alleles of these genes with MS was analyzed by transmission disequilibrium test (TDT). In investigated group of 104 nuclear families of Russian ethnicity it was found that TNF* (-308)A allele transmitted from healthy heterozygous parents to affected children more frequently (p = 0.01). Linkage/association of IFNG and IL-6 alleles with MS was not revealed. Thus, data obtained indicate the participation of TNF gene in MS susceptibility in Russians.