Hemophilia B

National Organization for Rare Disorders, Inc.

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Important
It is possible that the main title of the report Hemophilia B is not the name you expected.

Disorder Subdivisions

  • None

General Discussion

Summary
Hemophilia B is a rare genetic bleeding disorder in which affected individuals have insufficient levels of a blood protein called factor IX. Factor IX is a clotting factor. Clotting factors are specialized proteins needed for blood clotting, the process by which blood seals a wound to stop bleeding and promote healing. Individuals with hemophilia B do not bleed faster than unaffected individuals, they bleed longer. This is because they are missing a protein involved in blood clotting and are unable to effectively stop the flow of blood from a wound, injury or bleeding site. This is sometimes referred to as prolonged bleeding or a bleeding episode.

Hemophilia B is classified as mild, moderate or severe based upon the activity level of factor IX. In mild cases, bleeding symptoms may occur only after surgery, injury or a dental procedure. In some moderate and most severe cases, bleeding symptoms may occur after a minor injury or spontaneously, meaning without an identifiable cause.

Hemophilia B is caused by changes (mutations) in the factor IX gene on the X chromosome. Hemophilia B is mostly expressed in males but some females who carry the gene may have mild or, rarely, severe symptoms of bleeding.

Introduction
Hemophilia B, also known as factor IX deficiency or Christmas disease, is the second most common type of hemophilia. The disorder was first reported in the medical literature in 1952 in a patient with the name of Stephen Christmas. The most famous family with hemophilia B was that of Queen Victoria of England. Through her descendants, the disorder was passed down to the royal families of Germany, Spain and Russia and thus hemophilia B is also known as the "royal disease."

Although the focus of this report is the genetic, or inherited, form of hemophilia B, it should be noted that another form called acquired hemophilia B can develop, most commonly later in life (see "Related Disorders" section below). An individual with acquired hemophilia B is not born with the condition. Acquired hemophilia B is caused by the body's production of antibodies against its own factor IX protein. The factor IX antibodies destroy circulating factor IX in the blood causing bleeding symptoms. Acquired hemophilia B is extremely rare; most cases of acquired hemophilia are in those with hemophilia A.

Supporting Organizations

Canadian Hemophilia Society

301-666 Sherbrooke Street West
Montreal, QC H3A 1E7
Canada
Tel: 5148480503
Fax: 5148489661
Tel: 8006682686
Email: chs@hemophilia.ca
Website: http://www.hemophilia.ca

Genetic and Rare Diseases (GARD) Information Center

PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311
Website: http://rarediseases.info.nih.gov/GARD/

Hemophilia Federation of America

210 7th St. SE
Suite 200B
Washington, DC 20003
USA
Tel: (202)675-6984
Fax: (202)675-6983
Tel: (800)230-9797
Email: info@hemophiliafed.org
Website: http://www.hemophiliafed.org

NIH/National Heart, Lung and Blood Institute

P.O. Box 30105
Bethesda, MD 20892-0105
Tel: (301)592-8573
Fax: (301)251-1223
Email: nhlbiinfo@rover.nhlbi.nih.gov
Website: http://www.nhlbi.nih.gov/

National Hemophilia Foundation

116 West 32nd Street, 11th Floor
New York, NY 10001
USA
Tel: (212)328-3700
Fax: (212)328-3777
Tel: (800)424-2634
Email: handi@hemophilia.org
Website: http://www.hemophilia.org

World Federation of Hemophilia

1425, boul. René-Lévesque O.
Bureau 1010
Montréal, Québec, H3G 1T7
Canada
Tel: +1 (514) 875-7944
Fax: +1 (514) 875-8916
Email: wfh@wfh.org
Website: http://www.wfh.org/en/page.aspx?pid=492

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report.

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

Last Updated:  8/24/2016
Copyright  2015 National Organization for Rare Disorders, Inc.