MTHFR and Venous thrombosis: Among the venous thrombosis-related genes, MTHFR and PAI-1 were the two genes with the two highest percentage of mutation: MTHFR [C677T (65.3% vs. 57.9%) and A1298C (68.8% vs. 62.6%)], and PAI-1 (89.6% vs. 78.9%) (HH vs. Healthy, respectively groups).