Rare Bleeding Disorders

Factor XII (Hageman factor) deficiency

is a rare inherited disorder that affects a special protein that helps in the clotting process. A lack of factor XII does not cause abnormal bleeding, and there are usually no noticeable symptoms. For this reason, factor XII deficiency is usually found only as a byproduct of routine blood testing, as the blood takes longer to clot in a test tube.1


Factor XII deficiency is sometimes classified as having no clinical significance, and treatment is usually not needed. The outlook is usually good and there are usually no complications.1


  1. Factor XII (Hageman factor) deficiency. MedlinePlus website. http://www.nlm.nih.gov/medlineplus/ency/article/000545.htm. Accessed December 17, 2014.