Mild thrombophilia is considered to be one of the following: heterozygous factor V Leiden and prothrombin G20210A mutation, while protein C, S and antithrombin III deficiencies, antiphospholipid antibodies, and homozygous factor V Leiden are considered to be a severe form of thrombophilia [29]. The gene discussed is SERPINC1; the disease is thrombophilia.