Thrombosis in congenital deficiencies of AT III, protein C or protein S: a study of 44 children.

Congenital deficiency in coagulation inhibitors is a cause of hereditary thrombotic disease. The severity of symptoms is variable and depends on the type of deficit. In this paper, 44 children suffering from deep venous thrombosis, with a mean age of 5 years, were studied. A search for Lupus anticoagulant (LA) and coagulation inhibitor deficiency showed: 3/44 cases (6.8%) had protein S deficiency, 2/44 cases (4.5%) had protein C deficiency, 1/44 cases (2.3%) had deficiencies in both protein C and S; no cases of AT III deficiency and LA was positive in 2/44 cases (4.5%). Only 1 case of APC resistance out of 13 studied was found. Four family studies were performed and confirmed the congenital origin of the disorder.