Paraoxonase 2 (PON2) has antioxidant properties similar to paraoxonase-1 and paraoxonase-3. However, in contrast to paraoxonase-1 and paraoxonase-3, paraoxonase-2 is not associated with high-density lipoproteins and may only exert its antioxidant function at the cellular level. PON2 may also play a role in the pathogenesis of arterial thrombosis and atherosclerosis. The purpose of the present study was to investigate the possible association between the Cys311Ser polymorphism of PON2 gene and myocardial infarction (MI) in the Tunisian male population

A total of 700 unrelated Tunisian subjects including 321 patients with MI and 379 healthy controls were included in this study. Genomic DNA was extracted from peripheral blood leukocytes according to standard methods. PON2 genotypes were determined by PCRRFLP method.

A significant difference in genotype distribution and allele frequencies was observed between MI patients and controls. Patients with MI had a frequency of 17.1% for CC genotype, 45.8% for the CS genotype and 37.1% for the SS genotype. The controls had a frequency of 26.1% for the CC genotype, 45.6% for the CS genotype and 28.2% for the SS genotype (χ²=10.58; p=0.005). The MI patient group showed a significantly higher frequency of the S allele compared to the controls (0.60 vs 0.51; χ² =11.16; p<0.001). In multivariate analysis, C311S polymorphism was independently associated with MI (p<0.001).

Our results showed a significant and independent association between the PON2 C311S polymorphism (presence of S allele) and MI in the Tunisian male population.