miRNA polymorphisms and risk of premature coronary artery disease.

BACKGROUND: Several microRNA polymorphisms have been associated with susceptibility to specific health disorders, including cardiovascular diseases. The aim of the present study was to investigate whether four well-studied miRNA polymorphisms in non-Caucasian populations, namely miR146a G>C (rs2910164), miR149 C>T (rs2292832), miR196a2 C>T (rs11614913) and miR499 A>G (rs3746444), contribute to the risk for the development of premature Coronary Artery Disease (CAD) in the Greek population.

METHODS: We used a case-control study to examine these associations in 400 individuals: 200 CAD patients [including a subgroup of myocardial infraction (MI) patients] and 200 healthy controls, all of Greek origin. MiRNA polymorphisms were genotyped using three different assays: Polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP), High resolution Melting (HRM) and Sanger sequencing.

RESULTS: Two of these polymorphisms, miR196a2 C>T (rs11614913) and miR499 A>G (rs3746444) were found to be strongly associated with increased risk for CAD (p=0.0388 and p=0.0013, respectively) and for MI (p=0.0281 and p=0.0273, respectively). Furthermore, miR146C-miR149C-miR196T-miR499G allele combination appeared to be significantly related to CAD (p=0.0185) and MI (p=0.0337) prevalence.

CONCLUSIONS: Our results suggest that at least two of the studied polymorphisms, miR196a2 C>T (rs11614913) and miR499 A>G (rs3746444), as well as the miR146C-miR149C-miR196T-miR499G allele combination could represent useful biomarkers of CAD and/or MI susceptibility in the Greek population. These special genetic characteristics, in combination with environmental factors and personal habits, might contribute to CAD and/or MI prevalence.