[Is PLA1/A2 gene polymorphism of platelet membrane glycoprotein IIIa a risk factor for myocardial infarct?]. / Je PLA1/A2 polymorfizmus génu pre trombocytárny membránový glykoproteín IIIa rizikovým faktorom infarktu myokardu?

ABSTRACT

BACKGROUND: The PlA1/A2 polymorphism of the human platelet membrane glycoprotein IIIa gene cause T-->C transition in the exon ii (position 1565) resulting in the leucine-->proline substitution in amino-acid sequence. This polymorphism was shown to be associated with increased risk of myocardial infarction (MI). AIM: To test genetic parameters of the PlA1/A2 polymorphism in our population and to assess the relation between mutant PlA2 allele and MI. METHODS: DNA was isolated from peripheral blood, collected from 40 patients with MI and with present risk factors (hypertension, hypercholesterolaemia, diabetes, obesity, smoking...), 33 patients with MI without risk factors, 34 controls with equivalent average age to both groups of the MI-patients, 58 control probands without MI in their family history and 33 healthy controls randomly recruited. After PCR amplification the resulting 267 bp fragment was digested with the restriction endonuclease NciI and subfragments were separated electrophoretically in 12% polyacrylamide gel. RESULTS: The frequency of the PlA2 allele was 0.121 in patients with MI without risk factors, 0.205 in patients with present risk factors, 0.162 in controls of the equivalent average age to the MI-patients, 0.172 in controls without MI in their family history and 0.20 in healthy controls randomly recruited. Genotype frequencies were in all groups in genetic equilibrium. Although the groups differed significantly (p < 0.01) in serum concentrations of total cholesterol, HDL-cholesterol, LDL-cholesterol, apolipoprotein A-1, apolipoprotein B and malondialdehyde, no significant differences in the serum concentrations of these metabolites between A1/A1, A1/A2 and A2/A2 genotypes were observed. CONCLUSIONS: PLA1/A2 polymorphism is associated with MI, however not as a dominant risk factor, but as a part of environmentally influencable multigene system. There is no relation between genotypes of the PLA1/A2 polymorphism and the lipoproteins plasma concentrations. (Tab. 4, Ref. 17.)