New Hemophilia-like Disease Caused by Deficiency of a Third Plasma Thromboplastin Factor.

1. A third type of hemophilia characterized by a deficiency in a plasma thromboplastin factor other than anti-hemophilic globulin and plasma thromboplastin component (PTC) has been identified in 3 patients in one family, a maternal uncle and 2 nieces. 2. These patients reveal a mild hemorrhagic disease, and their clotting times are only moderately prolonged. 3. This newly described clotting factor, designated as plasma thromboplastin antecedent (PTA) is present in BaSO4-treated normal plasma and normal serum.