Antithrombin deficiency

Antithrombin Deficiency - Description, Causes and Risk Factors:

A plasma alpha2-globulin process that inhibits thrombin and has anticoagulant activities. Deficiency is commonly inherited as an autosomal dominant trait, caused by mutation in antithrombin III gene (AT3) or chromosome 1q; this is one of the few known mendelizing disorders from which thrombotic disease occurs.

antithrombin deficiency

Antithrombin is a protein that prevents too much blood clotting. Antithrombin deficiency is an inherited disorder that results in a lower level than normal of antithrombin in the blood. Antithrombin deficiency is rare, occurring in about 1 in 1000 people in the United States. Antithrombin deficiency can be inherited from one or both parents. This means that if one parent has it, then each child has a 50:50 chance of inheriting it. In some cases, antithrombin III deficiency may be acquired as a result of kidney or liver disease.

There is normally a careful balance of enzymes in the bloodstream; enzymes such as thrombin and factor X prevent the blood from becoming too thin, and chemicals such as antithrombin III and heparin prevent the blood from thickening. In the case of an antithrombin deficiency, coagulating enzymes prosper and the risk of clotting is high. In rare cases, patients may develop antithrombin deficiency as the result of some more serious underlying health condition, including:

  • Cancers.
  • Kidney failure.
  • Liver disease.
  • Nephrotic syndrome.
  • Physical trauma.
  • Systemic lupus erythematosus (SLE).
  • Truncus arteriosus.
  • Atrial septal defect.
  • Ventricular septal defect.

Risk Factors:

  • Bone marrow transplants.
  • Chemotherapy.
  • Medication that increases coagulation activity.
  • Medication that inhibits protein development.


Symptoms of Antithrombin Deficiency:

Patients will usually have symptoms of a blood clot, including:

  • Coughing up blood.
  • Chest pain.
  • Fainting.
  • Shortness of breath and pain when taking deep breaths.
  • Swelling of one leg.


A physical examination may show:

  • Abnormal lung sounds.
  • Fast breathing.
  • Fast heart rate.
  • Swollen foot or leg.

The diagnosis of antithrombin deficiency is made by a blood test that measures the amount of antithrombin in the blood. This test is usually performed in a Specialized laboratory.

Prothrombin time (PT) and activated partial thromboplastin time (aPTT): These studies allow evaluation of the presence of inappropriate activation of the Coagulation system.

  • Protein C or protein S deficiencies are both associated with venous thrombosis and are important exclusions in evaluating congenital deficiency of antithrombin.
  • The most common congenital procoagulant disorder, factor V Leiden, occurs in about 5% of patients and needs to be documented when attempting to make the diagnosis of congenital antithrombin deficiency. Knowing this level also helps to define a given patient's procoagulant risk.
  • Anticardiolipin antibodies (both immunoglobulin G [IgG] and immunoglobulin M [IgM] class): These should be measured by enzyme-linked immunosorbent assay (ELISA) or other physical means to rule out coexisting thrombotic risk from this source.


The primary goal of treatment is to prevent blood clots. The treatment you receive will depend on your history of previous blood clots, overall health, symptoms, and need for other medications or surgical procedures. The duration of treatment will vary depending on your individual medical history, and the presence of other health problems. Your treatment plan should be discussed with your Primary doctor or Hematologist. Some people with thrombophilia will never need treatment. Your doctor may recommend treatment with anticoagulant medications (blood thinners), such as heparin, low-molecular weight heparin, or warfarin to help prevent blood clots.

NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.

DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.


Submit a Comment

Your email address will not be published. Required fields are marked *

Cart Preview

Eating Vegetables, Fruit, and Fish May Keep Your Brain Sharp

Eating Vegetables, Fruit, and Fish May Keep Your Brain Sharp

A new study finds that brain volumes of people who regularly eat vegetables, fruit, and fish are on average 2ml greater than brain volumes of those who often drink sugary beverages. A brain volume reduction of 3.6ml equals to one year of aging. For the study, the...

Quiz about this article

Please answer on few questions to make our service more useful

Featured Products

Spring is Here: Top 6 Outdoor Sports

Good weather is the best reason to do outdoor sports, which will help not only lose weight, but also will strengthen health. Bicycle The sun dries out the local paths, so you can safely sit on your favorite bike and confidently twist the pedals, where the eyes look....

read more

First Aid in Case of Injuries for Sport and Exercise

First aid for injuries consists of simple rules that need to be clearly implemented. If this is a closed injury, you need to immobilize the injured limb, otherwise the person may lose consciousness from a painful shock. If you need to get to the emergency room...

read more