Genotype differences were also found (P=0.017) between FV R506Q heterozygotes (n=100) who had experienced previous VTE and those (n=100), who were still asymptomatic for VTE.
Resistance to activated protein C (APC resistance) due to the factor V mutation 506 Arg-->Gln (factor V Leiden) is the most prevalent inherited risk factor for venous thromboembolism.