A diagnostic work up for inherited causes of thrombophilia such as protein C and S deficiency, antithrombin III deficiency, factor V Leiden gene mutation (associated with activated protein C resistance), prothrombin gene mutation, hyperhomocysteinemia, elevated lipoprotein (a) and polycythemia vera revealed no pathology. This evidence concerns the gene PROC and hyperinsulinemic hypoglycemia, familial, 4.