Synergistic Impact of miR-126 and miR-143 Variants on Atherosclerosis Risk: A Case- Control Study Integrated with Functional In Silico Annotation

Atherosclerosis is a multifactorial vascular disease in which microRNA (miRNA) dysregulation and genetic variation contribute to disease susceptibility. This study investigated the individual and combined effects of the miR-126 rs4636297 and miR-143 rs4705342 polymorphisms on atherosclerosis risk in 400 Iranian individuals (200 patients and 200 controls) using Tetra-ARMS PCR, complemented by in silico functional annotation (VEP, RegulomeDB, and GTEx). Both variants were predicted to possess regulatory potential. The rs4636297 variant (RegulomeDB rank 1f) showed a strong eQTL effect on EGFL7 expression (NES = 0.44, P = 1.1 × 10⁻⁴⁹), whereas rs4705342 exhibited splice-related effects in arterial tissues (P < 10⁻²⁰). Clinically, the rs4636297 GG genotype (OR = 5.11, P < 0.001) and G allele (OR = 2.45, P < 0.001) were significantly associated with increased atherosclerosis risk, whereas the rs4705342 CC genotype (OR = 0.41, P = 0.038) and C allele (OR = 0.69, P = 0.031) conferred protection. Joint genotype analysis identified a significant gene–gene interaction, with the GG/TT combination conferring the greatest susceptibility (OR = 9.43, P = 0.001). Collectively, these findings identify a dual miRNA genetic axis influencing atherosclerosis susceptibility and demonstrate that integrating functional annotation with genotype profiling enhances the biological interpretation of genetic associations and may improve cardiovascular risk stratification.