Factor V Leiden (Arg506Gln), a confounding genetic risk factor but not mandatory for the occurrence of venous thromboembolism in homozygotes and obligate heterozygotes for cystathionine beta-synthase deficiency - Yap,S.; O'Donnell,K.A.; O'Neill,C.; Mayne,P.D.; Thornton,P.; Naughten,E. (Thromb Haemost, 1999)