SERPINC1 and protein S deficiency: In these 68 patients, 17 of them were further filtered out because these patients were found with heritable thromobophilias other than protein S deficiency (protein C deficiency (n = 1), antithrombin III (n = 1), immune problems (e.g., systemic lupus erythematosus (n = 2), anti-phospholipid antibody syndrome (n = 1)), or with other underlying medical conditions (e.g., diabetes mellitus (n = 1) and chronic hypertension (n = 1)), or carrying balanced translocation (n = 1).