The risk of thrombosis in the presence of FII G20210A mutation was 2.4 in homozygous and heterozygous, higher than the normal population, While the risk of thrombosis with factor V Leiden is 2.66 times higher than that of the patients negative for this mutation (OR 2.66 95% CI 0.96-7.37 P=0.059); according to ACOG (American College of and Gynecologists Women's Health Care 2013). The gene discussed is F5; the disease is Venous thrombosis.