[Hereditary deficit of antithrombin III].

Antithrombin III is a well-known coagulation inhibitor. Its heterozygous deficit is demonstrated through concentrations reduced about by 50 p. 100. On a clinical level, about 40 p. 100 to 70 p. 100 patients present with deep venous thrombosis (visceral on the whole) and pulmonary embolisms from puberty. There are both qualitative and quantitative deficits, these appearing to be mostly frequent. Only calculation of activity in the presence of heparin (co-factor of heparin) enables to diagnose these two types of deficits. Treatment performed includes both AT III concentrated agents and heparin in severe cases. Recurrences prevention is performed thanks to antivitamins K. If surgical treatment or delivery, a prevention of any incidents thanks to a vicarious therapy (AT III concentrated agent) is to be used.