Background: Coronary Artery Diseases (CAD) are the leading cause of
Myocardial Infarction (MI). However, their underlying etiology can be found in the interplay between environmental and genetic factors. On the other hand, it has been shown that Extracellular Matrix (ECM) proteins, such as Thrombospondins (TSP), play a crucial regulatory role in vascular pathologies, including atherogenesis. TSPs are extracellular proteins responsible for intercellular and cell-ECM interactions and are involved in regulating functional responses. Recently, a missense mutation in the TSP-۴ gene has been reported to potentially increase the risk of CADs. The present study aimed to investigate the role of rs۱۸۶۶۳۸۹ Guanosine to Cytosine (G/C) Single Nucleotide Polymorphism (SNP) of the TSP-۴ gene on the prevalence of premature MI in southern Iran.Methods: The present case-control study included ۱۰۰ patients with premature MI and ۱۰۰ healthy individuals. The DNA extracted from the blood samples of the participants underwent Polymerase Chain Reaction (PCR) for the sequence of the TSP-۴ gene. Afterward, the frequency of C (mutated) and G (normal) alleles of the TSP-۴ gene was evaluated in the case and control groups. Results: According to our findings, there was no significant intergroup difference in gender, age, and smoking status. However, the case group was significantly higher in the prevalence of Diabetes mellitus (DM), Hyperlipidemia (HLP), and Hypertension (HTN) compared to the control group. Moreover, ۲۲%, ۴۹%, and ۲۹% of the case group had CC, GC, and GG genotypes in the TSP-۴ gene, respectively, while the prevalence of CC, GC, and GG genotypes were ۱۰%, ۴۴%, and ۴۶% in the control group. Also, the prevalence of allele C was significantly higher in the case group (۴۷%) compared to the control group (۳۳%, P=۰.۰۴۳), showing its significant association with the increased risk of premature MI (OR = ۱.۸۰; ۹۵% CI = ۱.۰۱-۳.۱۹). Conclusions: The rs۱۸۶۶۳۸۹ G/C SNP of the TSP-۴ gene significantly increased the risk of premature MI in the population of southern Iran. Thus, such mutated gene can be used as a target for gene therapy or a marker for early detection of individuals at high risk for CADs.