| Description: |
Factor XI is a clotting protein synthesized in the liver. Congenital deficiency is inherited in an autosomal recessive pattern and is found most commonly in eastern European Ashkenazi Jews. In Ashkenazi Jews, the molecular defect has been found to be various point mutations which result in diminished or absent production of factor XI. Bleeding risk is variable in patients with factor XI deficiency. Patients with levels <10% of normal have a higher risk. Another risk factor is past bleeding events in the affected individual or kindred. Bleeding manifestations typically occur after invasive procedures or presents as mucosal bleeding. Deep bleeding into joints or muscles is unusual. Acquired inhibitors to factor XI have also been reported, usually in the setting of autoimmune disease. |
