Thrombosis-free survival curves of individuals with different FV genotypes. (A) Kaplan-Meier thrombosis-free survival analysis of the whole study cohort (probands and family members). (B) Kaplan-Meier thrombosis-free survival analysis of probands only. □, noncarriers; ○, FV Leiden heterozygotes; ▵, FV Leiden homozygotes; ♦, FV Leiden pseudohomozygotes. Differences between the curves were evaluated with the log-rank test. The apparently solid circles in the curve for FV Leiden heterozygotes are the effect of partial overlapping of open circles.