Spectrum and Prevalence of Prothrombotic Single Nucleotide Polymorphism Profiles in the Greek Cypriot Population.

Background. This study was performed to establish the allele, genotype and genotype combination/SNP (single nucleotide polymorphism) profile frequencies in the general population of Cyprus for 6 genes implicated in thrombotic disorders. The genes with their respective functional polymorphisms were the following: factor V (G1691A), prothrombin/factor II (G20210A), methylenetetrahydrofolate reductase (C677T), platelet glycoprotein receptor IIIa (P1A1/A2), β-fibrinogen (G/A-455) and plasminogen activator inhibitor-type 1 (4G/5G). Methods. DNA samples from 121 unrelated individuals were used for this epidemiological study. The polymerase chain reaction followed by restriction digestion were used to genotype the 6 different polymorphic loci. Allele and genotype frequencies were established and shown to be in Hardy-Weinberg equilibrium. Results. Mutant allele frequencies for the 6 genes were as follows: factor V-4%, prothrombin-2%, methylenetetrahydrofolate reductase -39%, platelet glycoprotein receptor IIIa-16%, β-fibrinogen-17% and plasminogen activator inhibitor - type 1-46%. Combined defects occurred which may increase the risk for vascular events, 33% of individuals (39/118) had 3 or more of the above mutations. Conclusions. As in other European populations, prospective case-control studies to estimate the risk for deep vein thrombosis (DVT) and ischemic episodes with respect to genetic and environmental risk factors should be performed. Thrombophilia screening should be applied for primary and secondary prevention of thrombotic episodes in susceptible individuals on the island of Cyprus. Individuals targeted for such screening include those with the following: a positive family history for thrombosis; a previous DVT or other ischemic episode; prior exposure to circumstantial risk factors and in the presence of echolucent plaques.