Concerning hypercoagulable syndromes, the following is/are true:

a. Acquired hypercoagulable states are more common than congenital disorders

c. Heparin associated thrombocytopenia is due to an antibody that attaches to the platelet Fc receptor

Acquired hypercoagulable states are much more common than congenital disorders at our present level of understanding. Fatal neonatal thrombosis is associated with homozygous ATIII deficiency. Heparin associated thrombocytopenia is associated with an IgG antibody that attaches at the Fc receptor and triggers platelet secretion and aggregation. The lupus anticoagulant is an antiphospholipid antibody that induces a thrombotic rather than a hemorrhagic disorder.