[Thrombophilia in a patient with congenital deficiency of AT III]

We describe a 43-year-old man with deep vein thrombosis and pulmonary thromboembolism. The initial treatment with heparin was unsuccessful. The patient's mother died of mesenteric vein thrombosis and his sister died at the age of 37 of cerebral arterial thrombosis. Haemostatis tests revealed normal screening tests of haemostasis, but decreased levels of abouth 50% of the normal level were established by the activity assay and immunological assay of AT III. The same level of AT III was found in the patients asymptomatic daughter. The patient was successfully treated with heparin combined with AT III concentrate and oral anticoagulants. On the basis of these laboratory findings and family data we established that the patient and his daughter had type I congenital AT III deficiency.