Congenital Antithrombin 3 Deficiency Overview
Learn About Congenital Antithrombin 3 Deficiency
Congenital antithrombin III (three) deficiency is a genetic disorder that causes the blood to clot more than normal.
Deficiency - antithrombin III - congenital; Antithrombin III deficiency - congenital
Antithrombin III is a protein in the blood that blocks blood clots from forming. It helps the body keep a healthy balance between bleeding and clotting. Congenital antithrombin III deficiency is an inherited disease. It occurs when a person receives one variant copy of the antithrombin III gene from a parent with the disease.
The variant gene leads to a low level of the antithrombin III protein. This low level of antithrombin III can cause blood clots (thrombi) that can block blood flow and damage organs.
People with this condition will often have blood clots at a young age for no reason. They are also likely to have family members who have had a blood clotting problem.
People will usually have symptoms of a blood clot. Blood clots in the arms or legs usually cause swelling, redness, and pain. When a blood clot breaks off from where it formed and travels to another part of the body, it is called a thromboembolism. Symptoms depend on where the blood clot travels to. A common place is the lung, where the clot can cause a cough, shortness of breath, pain while taking deep breaths, chest pain, and even death. Blood clots that travel to the brain can cause a stroke.
A blood clot is treated with blood-thinning medicines (also called anticoagulants). How long you need to take these medicines depends on how serious the blood clot was and other factors. Discuss this with your provider.
Maria Barrio-De La Morena practices in Murcia, Spain. Ms. Barrio-De La Morena is rated as an Elite expert by MediFind in the treatment of Congenital Antithrombin 3 Deficiency. Her top areas of expertise are Congenital Antithrombin 3 Deficiency, Factor 11 Deficiency, PMM2-Congenital Disorder of Glycosylation, and Blood Clots.
Belen Barrio-De La Morena practices in Murcia, Spain. Ms. Barrio-De La Morena is rated as an Elite expert by MediFind in the treatment of Congenital Antithrombin 3 Deficiency. Her top areas of expertise are Congenital Antithrombin 3 Deficiency, Factor 11 Deficiency, Blood Clots, and ALG6-CDG.
Carlos Perez-Bravo practices in Murcia, Spain. Mr. Perez-Bravo is rated as an Elite expert by MediFind in the treatment of Congenital Antithrombin 3 Deficiency. His top areas of expertise are Congenital Antithrombin 3 Deficiency, Factor 11 Deficiency, Adult T-Cell Leukemia, and Blood Clots.
More information and support for people with congenital antithrombin III deficiency and their families can be found at:
- National Organization for Rare Disorders -- rarediseases.org/rare-diseases/antithrombin-deficiency/
- MedlinePlus -- medlineplus.gov/genetics/condition/hereditary-antithrombin-deficiency/
- National Blood Clot Alliance -- www.stoptheclot.org/programs-services/
Most people have a good outcome if they stay on anticoagulant medicines.
Blood clots can cause death. Blood clots in the lungs are very dangerous.
See your provider if you have symptoms of this condition.
Once a person is diagnosed with antithrombin III deficiency, all close family members should be screened for this disorder. Blood-thinning medicines can prevent blood clots from forming and prevent complications from clotting.
Published Date: February 03, 2025
Published By: Warren Brenner, MD, Oncologist, Lynn Cancer Institute, Boca Raton, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Anderson JAM, Weitz JI. Hypercoagulable states. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 138.
Schafer AI. Thrombotic disorders: hypercoagulable states. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 67.