Background: Our aim in the present study was to determine whether endothelial NO synthase gene (ecNOS) polymorphisms are associated with myocardial infarction (MI).
Methods: Forty chromosomes from patients with MI were screened for polymorphisms of the ecNOS gene using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis and sequencing. Ten polymorphisms were detected: three in the 5' flanking sequence at positions -1474, -924 and -788, two in coding sequences 774C --> T (silent) and G894 --> T (Glu-298 --> Asp) and five in introns 2, 11, 12, 22 and 23. Five hundred and thirty-one patients with MI and 610 control subjects recruited in France and Northern Ireland in the ECTIM study were genotyped for these polymorphisms.
Results: Glu-298 homozygotes were more frequent among patients with MI than in control subjects in the French population [OR = 1.47 (1.03-1.97), P < 0.009], but no such difference was observed in Northern Ireland. No significant difference between cases and control subjects was detected for the other polymorphisms. Our search for a possible association of the combination of ecNOS polymorphisms with MI by logistic regression analysis was also negative.
Conclusions: We have explored a set of polymorphisms of the ecNOS gene in a large case-control study of MI and found that the polymorphisms were not consistently associated with MI.