1° case: Hereditary thrombophilia (Antiphospholipid antibody syndrome)2° case: Hereditary thrombophilia (prothrombin promoter G20210A mutation and 4G4G promoter mutation of the plasminogen activator inhibitor)3° case: Hereditary thrombophilia (mutation of 1691A gene for Factor V and mutation in C677T gene for methylenetetrahydrofolate reductase enzyme). The gene discussed is MTHFR; the disease is antiphospholipid syndrome.