Factor V Leiden in Patients with Venous Thrombosis in Slovak Population

Abstract. Resistance to activated protein C determined by factor V Leiden (FVL) is the most frequent inherited risk factor of venous thrombosis. The purpose of our work was to reveal the frequency of FVL in Slovak patients with venous thromboses, to characterise the nature of venous thromboses in this inherited thrombophilia, and to consider the screening approach to investigation of FVL in patients with venous thromboses. 350 patients with a diagnosis of venous thromboembolic disease from various regions of Slovakia were investigated. FVL, detected by polymerase chain reaction, was found in 128/350 (37%) patients with venous thromboses. 118/128 (92%) patients were heterozygous and 10/128 (8%) were homozygous carriers. In 108/128 (84%) patients with FVL the thromboembolic disease occurred spontaneously. Phlebothrombosis occurred predominantly in the lower limbs – 117/128 (91%) patients, atypical localisations were rare. The first thromboem-bolic event was manifested before 40 years of age in 69 % of patients. The family history was positive in 60/128 (47%) FVL carriers with thromboembolic disease