Risk factors and clinical presentation of venous thromboembolism according to the age of relatives of patients with factor V Leiden - Couturaud, Francis; Leroyer, Christophe; Dominique Mottier for the Groupe d’Etude de la Thrombose de Bretagne Occidentale (G.E.T.B.O) (Thrombosis and Haemostasis, 2008)