Glanzmann Thrombasthenia: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Glanzmann Thrombasthenia?
A hematologist, a doctor who treats blood and bleeding disorders, usually manages Glanzmann thrombasthenia. A primary care doctor may see you first for unusual bruising or bleeding. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is Glanzmann thrombasthenia?
Glanzmann thrombasthenia is a rare inherited bleeding disorder. It affects platelets, which are small cells in the blood that clump together to plug up bleeding spots. People with this condition bleed for a long time after injuries. The bleeding usually starts at birth.
It is estimated to affect 1 in one million people worldwide. Some people have mild bruising, while others have severe bleeding that can be life threatening.
Symptoms
Symptoms usually begin at birth or shortly after. They can vary greatly, even within the same family. Common signs include:
- Easy bruising, and small red or purple spots on the skin.
- Frequent nosebleeds.
- Bleeding gums.
- Heavy menstrual periods.
- Long bleeding after injuries, surgery, or dental work.
- Bleeding in the stomach or intestines, which often starts later in life.
- Rarely, bleeding in the joints or inside the skull, or blood in the urine.
Bleeding often becomes less frequent with age.
Causes and who gets it
Glanzmann thrombasthenia is caused by changes in the ITGA2B or ITGB3 gene. These genes make two parts of a protein called integrin alphaIIb/beta3. This protein sits on the surface of platelets. Without enough working protein, platelets cannot clump together to form a clot.
It is inherited in an autosomal recessive pattern. This means a child needs a changed gene from both parents. Parents who each carry one changed gene usually have no symptoms. For two carrier parents, each pregnancy has a 25% chance of an affected child.
The condition affects males and females equally. It is more common in some groups. Examples include people of Romani ethnicity, especially the French Manouche community. It is also more common where relatives often marry. Examples include parts of the Middle East, India, and France.
How doctors diagnose it
Most people with Glanzmann thrombasthenia have a normal platelet count. A bleeding time test measures how long a small, standard cut takes to stop bleeding. In this condition, that time is longer than usual. A platelet aggregation test then checks whether platelets clump together. In this condition, they do not clump as they should.
Lab tests can confirm the diagnosis by checking for the missing receptor on platelets. Genetic testing can find the changed ITGA2B or ITGB3 gene. Family members may also need to be tested.
Treatment
For most people this lifelong condition has no cure. Care focuses on controlling bleeding and preventing problems. Some people need platelet transfusions. These are donated platelets given to control severe bleeding. Transfusions may be needed throughout life. Some people develop antibodies that make later transfusions work less well.
Other treatments include antifibrinolytic medicines. These help control bleeding. A medicine called factor VIIa (NovoSeven RT) was approved in 2014. It treats bleeding and helps with surgery when platelet transfusions do not work. Hormonal therapy can suppress menstrual periods. Nosebleeds may be treated with nasal packing. A foam soaked in a clotting agent called thrombin can also be used. Regular dental care helps prevent bleeding from the gums.
A stem cell transplant from bone marrow or blood has cured several people with severe disease.
Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen stop platelets from clumping. This makes bleeding last longer. Anyone with a bleeding disorder should avoid taking them. Ask your doctor before taking any pain medicine.
Genetic counseling is recommended for people with this condition and their families.
When to see a doctor
Contact your health care provider if you have bleeding or bruising of an unknown cause.
Bleeding that is untreated, or does not respond to treatment, can be life threatening. Call 911 or go to the emergency room if you have heavy bleeding that will not stop, a head injury, a severe headache, or blood in your vomit.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. This type of doctor can do a first evaluation. They can also follow your bleeding over time and coordinate care with a hematologist.
Common questions
Is Glanzmann thrombasthenia life threatening?
It can be. Bleeding that is untreated or not controlled can be life threatening. Some people have mild bruising, and bleeding often becomes less frequent with age.
Can Glanzmann thrombasthenia be cured?
Usually not, because it is a lifelong condition. A stem cell transplant has cured several people with severe disease.
Can Glanzmann thrombasthenia be prevented?
No. It is inherited, so it cannot be prevented. Genetic counseling can help families understand their risk.
Is pregnancy safe for women with Glanzmann thrombasthenia?
Pregnancy carries extra risk. Women with this condition have an increased risk of excessive blood loss during pregnancy and childbirth. Platelet transfusions are usually needed before delivery.
Sources
- MedlinePlus Genetics - Glanzmann thrombasthenia
- MedlinePlus Medical Encyclopedia - Glanzmann thrombasthenia
- National Organization for Rare Disorders (NORD) - Glanzmann Thrombasthenia
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
