| Description: |
Factor VII is a vitamin K-dependent glycoprotein synthesized in the liver and by activated monocytes. It circulates in an inactive zymogen form and has the shortest half-life of the vitamin K-dependent clotting factors (4-5 hours). Congenital deficiencies are inherited in an autosomal recessive pattern. Common causes of acquired factor VII deficiency include liver disease and Coumadin® therapy.
Note: acquired inhibitors to factor VII are rare. The classic laboratory presentation of factor VII deficiency is a prolonged prothrombin time, a normal APTT, and normal thrombin time. The diagnosis is confirmed by the factor VII assay. |
