Skip to main content
MyKelseyOnline
Spanish Version
 
E-mail Form
Email Results

 
 
Print-Friendly
Bookmarks
bookmarks-menu

Factor XII (Hageman factor) deficiency

F12 deficiency; Hageman factor deficiency; Hageman trait; HAF deficiency

Factor XII deficiency is an inherited disorder that affects a protein (factor XII) involved in blood clotting.

Causes

When you bleed, a series of reactions take place in the body that helps blood clots form. This process is called the coagulation cascade. It involves special proteins called coagulation or clotting factors. You may have a higher chance of excess bleeding if one or more of these factors are missing or are not functioning as they should.

Factor XII is one such factor. A lack of this factor does not cause you to bleed abnormally. But, the blood takes longer than normal to clot in a test tube.

Factor XII deficiency is a rare inherited disorder.

Symptoms

There are usually no symptoms.

Exams and Tests

Factor XII deficiency is most often found when clotting tests are done for routine screening.

Tests may include:

  • Factor XII assay to measure the activity of factor XII
  • Partial thromboplastin time (PTT) to check how long it takes for blood to clot
  • Mixing study, a special PTT test to confirm factor XII deficiency 

Treatment

Treatment is usually not needed.

Support Groups

These resources can provide more information on factor XII deficiency:

Outlook (Prognosis)

The outcome is expected to be good without treatment.

Possible Complications

There are usually no complications.

When to Contact a Medical Professional

The health care provider usually discovers this condition when running other lab tests.

Prevention

This is an inherited disorder. There is no known way to prevent it.

References

Gailani D, Wheeler AP, Neff AT. Rare coagulation factor deficiencies. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 137.

Hall JE. Hemostasis and blood coagulation. In: Hall JE, ed. Guyton and Hall Textbook of Medical Physiology. 13th ed. Philadelphia, PA: Elsevier; 2016:chap 37.

Ragni MV. Hemorrhagic disorders: coagulation factor deficiencies. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 174.

  • Blood clots

    Blood clots - illustration

    Blood clots (fibrin clots) are the clumps that result when blood coagulates.

    Blood clots

    illustration

    • Blood clots

      Blood clots - illustration

      Blood clots (fibrin clots) are the clumps that result when blood coagulates.

      Blood clots

      illustration

    Tests for Factor XII (Hageman factor) deficiency

     
     

    Review Date: 1/29/2019

    Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

    The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
    adam.com

     
     
     

     

     

    A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.
    Content is best viewed in IE9 or above, Firefox and Google Chrome browser.