A CASE OF PROTEIN-C DEFICIENCY ASSOCIATED WITH CEREBRAL INFARCTION AND OBSTRUCTION OF DEEP LEG AND INFERIOR MESENTERIC VEINS

Protein C, a vitamin K-dependent protein, is a blood coagulation inhib itor. Its deficiency causes systemic thrombosis. A 31-year-old woman d eveloped cerebral infarction followed by late psychomotor seizures, an d thrombosis in the inferior mesenteric vein and bilateral crural vein s. Her parents were first cousins. Her mother died of cerebral thrombo sis in her 30's. Her elder brother died of suspected purpura fulminans immediately after birth. Her protein C activity and protein C antigen level decreased markedly and were less than 5% of those of normal con trols and 0.3 mug/ml, respectively. Her father, a paternal aunt and a maternal uncle also showed a low protein C activity and protein C anti gen level. This patient seems to have congenital protein C deficiency which produced thrombosis in the leg veins and the mesenteric vein, pr obably cerebral infarction.