impact of il-21 gene polymorphisms (rs2055979) and the levels of serum il-21 on the risk of multiple sclerosis

Multiple sclerosis (ms) is a chronic autoimmune disorder of the central nervous system. genetic and environmental factors have important roles in the induction, onset, and progression of ms. in this study, the il-21 genotype (rs2055979) (g/t) in iraqi ms patients was compared with a healthy control group to investigate the possible association of any particular genotype or allele with multiple sclerosis. this study included 70 patients with relapsing-remitting ms and 50 healthy individuals as control. following the extraction of genomic dna, polymerase chain reaction-restriction fragment length polymorphism, the frequencies of genotypes, and alleles were calculated and statistically analyzed. the results of the study revealed a significant reduction in the distribution of the wild homozygous genotype (gg) in ms patients, in comparison to a healthy control group (14.3% vs. 34 %; 0.0129 at p≤0.05; odds ratio [or] 3.0909, 95% confidence interval [ci]: 1.2704-7.5203). however, ms cases and controls did not differ significantly in neither gt nor tt genotypes, 62.9% (or 0.6402, 95% ci: 0.3064-1.3374) and 52% (or 0.5494, 95% ci: 0.2074-1.4557), respectively. the data of allele frequencies in patients and controls showed that the g allele frequencies were 0.46 vs. 0.60 in patients and controls, respectively, while t allele frequencies were 0.54 vs. 0.40 in patients and controls, respectively. the current conclusions indicated that in the study group, the gg genotype of il-21(rs2055979) could be related to ms.