Introduction: Inherited and aquired factors are important in the pathogenesis of thrombosis. Recent studies have demonstrated that mutations in the genes encoding coagulation factor V (FVQ506 or FVLeiden) and prothrombin (PT 20210 A) predispose to a markedly increased risk of venous thrombosis. FVQ506 is considered to be the most frequent cause of inherited venous thrombosis in Europeans and the allele frequency has been shown to be high. The aim of this study was to determine the allele frequency of the two mutations in an apparently healthy Icelandic population and patients suffering from venous thrombosis.
Material and methods: An apparently healthy Icelandic population and patients suffering from venous thrombosis were genotyped for the presence or absence of the FVQ506 and PT 20210 A mutations using PCR and restrictions fragment length polymorphisms.
Results: The allele frequency of FVQ506 was 0.0315 in the healthy population (n=159; 10 heterozygotes found). Fifteen of 99 patients with venous thrombosis were found to be heterozygous for FVQ506 (15.2%; allele frequency 0.071), significantly more when compared to controls (p<0.01). One apparently healthy individual (0.9%; n=108) and one of the patients (0.95%; n=99) were found to be heterozygous for PT 20210 A.
Conclusion: The results demonstrate high prevalence of FVQ506 in the Icelandic population compared with many other European populations and that FVQ506 is commonly associated with venous thrombosis.