Association study of common genetic variants in pre-microRNAs in patients with ulcerative colitis

Background: Common single-nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human diseases. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre-miRNAs (miR-196a2, miR-146a, and miR-499) with the risk of ulcerative colitis (UC) in a Japanese population. Methods: The rs11614913 (T>C), rs2910164 (C>G), and rs3746444 (A>G) SNPs were genotyped in 170 UC and 403 control subjects. Results: The rs3746444 AG genotype was significantly higher among the UC group (odds ratio (OR)=1.51, 95% CI=1.03-2.21, p=0.037). The rs3746444 AG genotype was associated with onset at an older age (OR=1.70, 95% CI=1.04-2.78, p=0.035), left-sided colitis and pancolitis (left-sided colitis, OR=2.10, 95% CI=1.12-3.94, p=0.024; pancolitis, OR=1.81, 95% CI=1.09-3.01, p=0.028, left-sided colitis+pancolitis, OR=1.91, 95% CI=1.26-2.92, p=0.003), higher number of times hospitalized (OR=2.63, 95% CI=1.22-5.69, p=0.017), steroid dependence (OR=2.63, 95% CI=1.27-5.44, p=0.014), and refractory phenotypes (OR=2.76, 95% CI=1.46-5.21, p=0.002) while the rs3746444 AA genotype was inversely associated with the number of times hospitalized (2∼, OR=0.36, 95% CI=0.17-0.79, p=0.012), steroid dependence (OR=0.42, 95% CI=0.21-0.88, p=0.021), and refractory phenotypes (OR=0.38, 95% CI=0.20-0.72, p=0.003). The rs1161913 TT genotype also held a significantly higher risk of refractory phenotype (T/T vs. T/C+C/C, OR=2.21, 95% CI=1.17-4.18, p=0.016). Conclusions: Our results provided the first evidence that rs3746444 SNP may influence the susceptibility to UC, and both rs3746444 and rs11614913 SNPs may influence the pathophysiological features of UC.