Association of interleukin-17F (rs763780) single nucleotide polymorphism with multiple sclerosis and optic neuritis.

IL-17F single nucleotide polymorphism (SNP) can affect IL-17F expression and activity and this can lead to the increased susceptibility to several autoimmune diseases. The aim was to investigate the association of IL-17F (rs763780) SNP with the development of multiple sclerosis (MS) in a cohort of Egyptian patients and to evaluate the effect of this polymorphism on the disease course. IL-17F (rs763780) gene polymorphisms was typed by TaqMan genotyping assay for 231 Egyptians divided into 102 MS patients and 129 healthy controls with matched age and sex. The IL-17F rs763780 C containing genotypes (CT+CC) and C allele have statistically significant increased frequency in MS patients when compared with controls (p = 0.005 and 0.004 respectively) especially in females' patients (p = 0.005 and 0.006 respectively). The heterozygous CT genotype was associated with the presence of optic neuritis (p = 0.038). The multivariable regression analysis revealed significant associations between smoking, the higher frequency of attacks and the prediction of higher EDSS score (p = 0.032, 0.049 respectively). It can be concluded that the IL-17F rs763780 C containing genotypes (CT and CC) and C allele may be risk factors for the development of MS in the studied Egyptian cohort by a gender-dependent mechanism that contributes to tendency for predisposition in females and optic neuritis is more common in patients carrying the CT heterozygous genotype.