Increased Risk of Multiple Sclerosis in the Presence of a Genetic Variant in 19-Nucleotide Downstream of miR-148a Coding Gene in Isfahan City Population in Iran

Multiple sclerosis (MS) is a common disease of the central nervous system, and the incidence of this disease in women is twice that of men. Considering the importance of miRNA polymorphisms in the expression and function of mRNAs as well as the risk of disease, this study investigated the association of rs6977848 polymorphism (a genetic variant in 19-nucleotide downstream of miR-148a coding gene) with the risk of MS disease in Isfahan City population in Iran, for the first time.

In this case-control study, a population of 95 healthy individuals and 99 patients were assayed. The genotype of the individuals for the polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). To confirm the results, a number of samples were sequenced. Then, the frequency of genotypes and alleles were evaluated.

Considering the total dominance of T allele, the total TT and TG genotypes significantly increased the susceptibility to MS disease compared with the GG reference genotype [odds ratio (OR) = 2.27, P = 0.043); while considering the genotype GG as reference genotype, there was a significant difference between the TG and the reference genotypes in this population with a risk of disease (P < 0.050). However, no significant difference was observed between genotype TT and GG genotype as reference genotype.

Findings indicate that rs6977848 polymorphism in miR-148a coding gene downstream may be effective in influencing the performance of this miRNA as well as its expression level. Moreover, the incidence of the ability of individuals to affect this disease is not significantly related to the incidence of disease in the studied populations.