Objectives: Single nucleotide polymorphisms (SNPs) in microRNA (miRNA) genes can have diverse functional consequence by affecting the processing and target selection of miRNA. Recent evidence indicates that miRNA play important roles in the pathogenesis of atherosclerosis, which is a major cause of ischemic stroke (IS). The aim of this study was to clarify whether genetic variations in four miRNA genes (miR-143 rs4705342, miR-122 rs17669, miR-126 rs4636297, and miR-124 rs531564) contribute to IS susceptibility. Methods: A case-control study was used to explore miRNA genetic polymorphisms in 567 IS patients and 552 control subjects that were frequency matched by age and gender. We genotyped four SNPs using polymerase chain reaction/ligation detection reaction. Results: The miR-126 gene rs4636297 polymorphism was associated with decreased small vessel stroke risk (GA vs. GG: odds ratio (OR) = 0.62, p = .015; GA + AA vs. GG: OR = 0.637, p = .018; A vs. G: OR = 0.696, p = .033). Using logistic regression analysis, this significant association remained after adjusting for confounding risk factors (adjusted OR = 0.626, 95% confidence interval (CI) = 0.426-0.921). However, the three other miRNA (miR-143 rs4705342, miR-122 rs17669, and miR-124 r531564) were not associated with IS risk under allele or genotype, nor in different inheritance models. In addition, there were no significant associations with stroke subtypes for these three miRNA SNPs. Conclusion: Our study suggests that the miR-126 gene rs4636297 polymorphism may play an important role in the pathogenesis of small vessel occlusive stroke in the northern Chinese Han population.
Keywords: Ischemic stroke; miR-122; miR-124; miR-126; miR-143; polymorphisms.