Inherited risk factors for venous thromboembolism: implications for clinical practice.

Each year, thrombosis in the deep veins of the lower extremities occurs in 1 of every 1000 Americans (1). Although most cases of venous thrombosis are not fatal, death from pulmonary embolism can be expected in 1% to 2% of all patients, and as many as 25% of patients with deep venous thrombosis (DVT) will suffer the chronic effects of postthrombotic syndrome. Thus, identification of high-risk patients with genetic predispositions to thrombosis is an important clinical goal, particularly among individuals with recurrent DVT.