Antithrombin Deficiency

National Organization for Rare Disorders, Inc.

It is possible that the main title of the report Antithrombin Deficiency is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • AT 3
  • AT III deficiency
  • thrombophilia, hereditary, due to AT III

Disorder Subdivisions

  • None

General Discussion

Antithrombin deficiency is a blood disorder characterized by the tendency to form clots in the veins (thrombosis). An inherited tendency to thrombosis is known as thrombophilia. Antithrombin is a substance in the blood that limits the blood's ability to clot (coagulation). In people with congenital antithrombin deficiency, there is a reduced amount of this substance in the blood due to a genetic abnormality. Antithrombin deficiency may also be acquired; in such cases, the disorder may be reversible with treatment.


March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
Tel: (914)997-4488
Fax: (914)997-4763

American Liver Foundation
39 Broadway, Suite 2700
New York, NY 10006
Fax: (212)483-8179
Tel: (800)465-4837

NIH/National Heart, Lung and Blood Institute
P.O. Box 30105
Bethesda, MD 20892-0105
Tel: (301)592-8573
Fax: (301)251-1223

Vascular Disease Foundation
550 M Ritchie Highway
Severna Park, MD 21146
Tel: (443)261-5564
Tel: (888)833-4463

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
TDD: (888)205-3223

National Blood Clot Alliance
120 White Plains Road
Suite 100
Tarrytown, NY 10591
Tel: (914)220-5040
Tel: (877)466-2568

Venous Disease Coalition
1075 S. Yukon Street, Suite 320
Suite 320
Lakewood, CO 80226
Tel: (303)989-0500
Fax: (303)989-0200
Tel: (888)833-4463

For a Complete Report

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The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

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.

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Last Updated:  8/2/2012
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