| Description: |
Factor XII is a clotting factor synthesized in the liver, and participates in contact-mediated activation of coagulation. The physiologic significance of factor XII in hemostasis is unclear in that severely deficient patients do not have a bleeding diathesis. Factor XII deficiency is usually discovered as an incidental finding in a patient with a prolonged PTT and no bleeding history. Congenital deficiency is inherited as an autosomal recessive trait. Acquired deficiency is most commonly seen in patients with nephrotic syndrome. Although there have been several reports of factor XII deficiency and thrombosis, this association remains unproven; animal models suggest that deficiency may protect from thrombotic challenges. |
