Genetic variants of platelet ADP receptor P2Y12 associated with changed platelet functional activity and development of cardiovascular diseases

The key role in platelet aggregation is played by the platelet ADP receptor P2Y12, which is the target for antiaggregant drugs, clopidogrel and ticlopidine. At present, only sporadic data on genetic variants of platelet ADP receptor P2Y12 are available from literature, and their association with thromboembolic and cardiovascular diseases still remains obscure. Analysis of the group of subjects with high platelet reactivity resulted in identification of two nucleotide substitutions, C18T and G36T, in the coding region of the P2Y12 gene. The frequency of the P2Y12 T18 allele was higher in control group than in the group of patients survived from myocardial infarction at the age under 45 years (39% versus 28%, respectively, P = 0.04). Moreover, in the T18 carriers, platelet aggregation activity was lower than in the carriers of the wild-type genotype (0.84 +/- 0.05%/s versus 1.01 +/- 0.08%/s, respectively, P = 0.03). In the group of patients with early myocardial infarctions, a tendency towards the increased frequency of T36 allele in comparison with control group (20 and 12%, respectively, P = 0.07) was observed. The rate of ADP-induced platelet aggregation in the carriers of T36 allele from the control group was somewhat higher than in the subjects with the GG36 genotype (1.31 +/- 0.16%/s versus 1.12 +/- 0.06%/s, respectively, P = 0.07). The nucleotide substitutions identified were in lincage disequilibrium, i.e., allele T18 conformed to allele G36. On the contrary, allele C18 conformed to allele T36. Haplotype T18G36 was found to be responsible for the decreased risk of myocardial infarction and decreased platelet reactivity. It is suggested that polymorphisms of the P2Y12 gene identified can be used for determination of the risk group for myocardial infarction in the young males.