Increased risk for venous thrombosis in carriers of the prothrombin G→A20210 gene variant

A mutation in the prothrombin gene (G--A20210) has been associated with higher plasma prothrombin levels and an increased tendency for venous thrombosis.To determine whether the prothrombin A20210 allele is independently associated with the occurrence of venous thrombosis.Case-control study.Two thrombosis centers in southern Italy.281 consecutive patients with venous thrombosis confirmed by objective tests and 850 controls.Medical history was collected on standardized questionnaires. The presence of prothrombin G--A2020 and factor V Leiden mutations was determined by polymerase chain reaction. The presence of anticoagulant factors and prothrombin activity was determined by tests of function…