Background Recent emerging evidence supports the role of miR-196a2 in various human diseases. However, its role in type 1 diabetes mellitus (T1DM) is still underestimated. We aimed, for the first time, to investigate the expression of miR-196a2 in T1DM and the association of miR-196a2 (rs11614913) polymorphism with susceptibility of T1DM in a sample of patients from Cairo, Egypt. Methods The study included 150 patients and 150 healthy subjects. Evaluation of rs11614913 genotypes and miR-196a2 expression was done using the allelic discrimination and quantitative reverse transcriptase polymerase chain reaction (PCR) method, respectively. Results The Hardy-Weinberg equilibrium of single nucleotide polymorphism(SNP) was detected among controls (p = 0.2). Our results revealed that the TT genotype was more frequent in patients (22.6%) than controls (10%) while the CC genotype was more frequent in controls (47.3%) than patients (39.3%) (p = 0.01). The frequency of the T allele was significantly higher in patients than in controls (41.7 vs. 31.3%), while the C allele was more frequent in controls (p = 0.008). After adjustment for traditional risk factors, the association of the TT genotype with T1DM remained significant (TT vs. CC, odds ration [OR] = 3.2, 95% confidence interval [CI]: 1.4-7.4, p = 0.005). Power analysis of the data yielded a statistical power of 80% for the miR-196a2 rs11614913 with T1DM. Relative expression of miR-196a2 showed significant decrease in patients compared to controls (median = 0.09, 0.5, interquartile range [IQR] = 0.03-1.6, 0.1-2.1). However, miR-196a2 expression showed no significant difference between different rs11614913 genotypes (p = 0.5). Conclusions Our findings demonstrated that miR-196a rs11614913 is associated with T1DM and decreased expression of miR-196a2 may play a role in pathogenesis of T1DM.
Keywords: T1DM; expression; miR-196a2; polymorphism; rs11614913.