Compared to controls, patients with isolated DVT, DVT plus PE, and isolated PE showed significantly higher frequencies for the following-heterozygous FVL mutation, isolated DVT (28.3%), DVT plus PE (44.2%), isolated PE (50%), controls (8.3%; P < .001); heterozygous PTG mutation, isolated DVT (11.3%), DVT plus PE (20.9%), isolated PE (25%), controls (5.9%; P < .01); Apo E 2/4, isolated DVT (9.7%), DVT plus PE (9.3%), isolated PE (5%), controls (1%; P < .01).The MTHFR A1298C mutation showed a significantly higher frequency in isolated patients with PE than in those with isolated DVT ( P = .006) and in controls ( P = .008).