A common mutation in the methylenetetrahydrofolate reductase gene (C677T) increases risk for deep-vein thrombosis in patients with mutant factor V (factor V:Q506) Arterioscler - Cattaneo, M; Tsai, MY; Bucciarelli, P; Taioli, E; Zighetti, ML; Bignell, M; Mannucci, PM (Thromb Vase Biol, 1997)