Thrombophilia was identified in 10 patients, protein C deficiency (n = 4), protein S deficiency (n = 3), antithrombin III deficiency (n = 2), factor V Leiden syndrome (n = 1), and antiphospholipid syndrome (n = 2). The gene discussed is SERPINC1; the disease is hereditary thrombophilia due to congenital protein S deficiency.