Clotting factor V has a dual function in coagulation: after activation, procoagulant factor V stimulates the formation of thrombin, whereas anticoagulant factor V acts as a cofactor for activated protein C (APC) in the degradation of factor VIII/VIIIa, thereby reducing thrombin formation. In the present study, we evaluated whether plasma factor V levels, either decreased or increased, are assoc...

It has autosomal dominant inheritance and is the most common cause of inherited thrombophilia. FVL is the most prevalent thrombotic risk factor known in the Caucasian population (around 5%). [1] Heterozygotes have a three to five times increased risk of thrombosis. Homozygotes are much less common but have a much higher thrombotic risk, around eight times increased risk. It leads to a hypercoag...

Background: Activated protein C (APC) inactivates factor V (FV) by cleavage of its heavy chain at Arg306, Arg506, Arg679, and Lys994. Mutational changes, which abolish APC cleavage sites, may predispose thrombosis by altering the inactivation process of FV. FV Leiden (FVL) (Arg506Glu) has been demonstrated as a strong risk factor for thrombosis. In the current study, we have studied whether mut...

In a collaborative multicenter case-control study, we investigated the effect of factor V Leiden mutation, prothrombin gene mutation, and inherited deficiencies of protein C, protein S, and antithrombin on the risk of Budd-Chiari syndrome (BCS) and portal vein thrombosis (PVT). We compared 43 BCS patients and 92 PVT patients with 474 population-based controls. The relative risk of BCS was 11.3 ...

OBJECTIVE To confirm the relationship between resistance to activated protein C (APC), factor V Leiden, and central retinal vein occlusion in young adults as reported in a recent study of patients younger than 50 years. PATIENTS AND METHODS Patients younger than 50 years with central retinal vein occlusion were identified from the medical records of the Wills Eye Hospital Retina and Retina Va...

BACKGROUND AND PURPOSE Reocclusion of intracranial arteries after successful recanalization is associated with poor clinical outcome. The role of Factor V Leiden mutation in intracranial arterial thrombosis/rethrombosis is unclear. SUMMARY OF REPORT We report the case of a patient who developed recurrent reocclusions of the middle cerebral artery after intra-arterial thrombolysis for acute is...

Through modification of an in vitro test for thrombosis formation, a Dutch research group has made three significant findings: 1) third-generation oral contraceptives (OCs) induce a resistance to the blood's natural anticoagulation system of a magnitude close to that induced by a mutation in coagulation factor V Leiden; 2) second-generation OCs show only part of the effect; and 3) in OC users h...

Factor V Leiden (FVL) is the most common known inherited cause of thrombophilia; it is present in approximately 5% of the Caucasian population. Although the risk of venous thrombosis associated with this polymorphism in various medical settings is well described, its effect on perioperative risk is only beginning to be explored. Specifically, there are few studies addressing the potential risks...

In a collaborative multicenter case-control study, we investigated the effect of factor V Leiden mutation, prothrombin gene mutation, and inherited deficiencies of protein C, protein S, and antithrombin on the risk of Budd-Chiari syndrome (BCS) and portal vein thrombosis (PVT). We compared 43 BCS patients and 92 PVT patients with 474 population-based controls. The relative risk of BCS was 11.3 ...

BACKGROUND AND OBJECTIVES In this retrospective, single center, cohort study we assessed the risk of pregnancy-related venous thromboembolism (VTE) in women belonging to a large number of families identified because of a symptomatic proband with single identified factor V Leiden mutation. DESIGN AND METHODS Female family members who had experienced at least one full-term pregnancy were enroll...