Angiotensin Converting Enzyme Gene Insertion/Deletion Polymorphism (rs4646994) in Acute Coronary Syndrome

Introduction: Acute coronary syndrome (ACS) is a leading cause of death in India and is affected by both genetic and environmental factors. The angiotensin-converting enzyme (ACE) gene’s insertion/deletion (I/D) polymorphism (rs4646994) has been linked to cardiovascular risk, but its connection to ACS in South Indian populations is not well studied. This case-control study aimed to explore this relationship by comparing 81 ACS patients with 81 matched controls. Material and Methods: Genotyping was done using PCR and Sanger sequencing. We analyzed genotype and allele frequencies with chi-square tests and logistic regression. Results: Among patients, the genotype distribution was 29.6% II, 51.9% ID, and 18.5% DD. In contrast, controls had 45.7% II, 43.2% ID, and 11.1% DD. We did not find any significant difference in genotype frequencies (p > 0.05). However, logistic regression showed that the ID genotype was linked to a lower risk of ACS (OR = 0.50, 95% CI = 0.75–4.43, p = 0.02). The DD genotype did not show a significant connection (p = 0.13). The dominant model (ID+DD vs II) indicated an increased ACS risk (OR = 1.99, 95% CI = 1.04–3.81, p = 0.02). Overall, the ACE I/D polymorphism did not show a consistent link to ACS in this group, which may reflect genetic diversity in the region. Conclusion: Our study found no consistent overall association between ACE I/D polymorphism (rs4646994) and ACS, though the ID genotype appeared protective and the dominant model (ID+DD) suggested increased risk. These findings indicate a possible role of ACE polymorphism in ACS susceptibility among South Indians, warranting larger multicenter studies for confirmation.