hematology and oncology
Uncommon Hereditary Coagulation Disorders
Factor XI deficiency
Factor XI deficiency is uncommon in the general population but common among patients of Ashkenazi Jewish ancestry (gene frequency about 5 to 9%). Bleeding typically occurs after trauma or surgery in people who are homozygotes or compound heterozygotes for factor XI gene abnormalities. There is no precise relationship between the plasma factor XI level and severity of bleeding. 