The risk of recurrent venous thromboembolism in patients with an Arg 506 - Gln mutation in the gene for factor V (Factor V Leiden) - Siminoni, P; Pranondoni, P; Lensing, AWA; Scudeller, A; Sardella, C; Prins, MH; Villalta, S; Dazzi, F; Girolami, A (N Engl J Med, 1998)