Abstract: Background: Matrix metallopeptidase-9 (MMP-9) plays a pivotal role in vascular remodelling and development of atherosclerotic lesion. The potentially functional MMP-9 polymorphisms may contribute to the susceptibility of Acute Coronary Syndrome (ACS). Objectives: Our aim was to examine whether MMP9-1562C/Tpolymorphism is associated with susceptibility to acute
coronary syndrome (ACS) in the Egyptian population. Methods: This case-control study was composed of 80 ACS patients and 40 control subjects. The ACS group included 40 patients with Acute Myocardial Infarction (AMI) and 40 patients with Unstable Angina Pectoris (UAP). The genotypes of MMP-9 -1562 C/T polymorphism was determined by the method of polymerase chain reaction and restriction fragment length polymorphism (RFLP-PCR). The relationship between the polymorphism of the MMP-9 gene and Acute
Coronary Syndromewas analysed. Results: The genotype frequencies for CT+TT genotypes and the −1562T allele were significantly higher in the ACS group than in the control group (25% vs. 0.0% and 20.4% vs. 0.0%, P=0.001and P=0.004, respectively). The T allele carriers had an approximately 1.51 -fold higher risk of developing ACS than those with the CC homozygote (OR=1.51; 95% CI, 1.33–
1.72). While there was no statistically significant difference between patients with acute myocardial infarction and unstable angina
pectoris regarding genotypes and allele frequencies (P > 0.05). Conclusion: MMP-9-1562C>T polymorphism is associated with the susceptibility to ACS in the Egyptian population.But there was no significant difference between the AMI and UAP subgroups.