National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Glanzmann thrombasthenia



Other Names:
Thrombasthenia of Glanzmann and Naegeli; GT; Platelet fibrinogen receptor, deficiency of; Thrombasthenia of Glanzmann and Naegeli; GT; Platelet fibrinogen receptor, deficiency of; Platelet glycoprotein 2B 3A deficiency; Deficiency of GP 2B 3A complex; Glanzmann thrombasthenia type A; Diacyclothrombopathia 2B 3A See More
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Glanzmann thrombasthenia (GT) is a rare inherited blood clotting disorder that is present at birth. It is characterized by the impaired function of specialized blood cells, called platelets, that are essential for proper blood clotting. Signs and symptoms vary greatly from person to person. Symptoms usually include abnormal bleeding, which can be severe. Other symptoms may include easy bruising, nose bleeds, bleeding from the gums, and/or heavy menstrual bleeding. Rarely, internal bleeding and blood in the urine (hematuria) can occur. Prolonged untreated or unsuccessfully treated bleeding may be life threatening. This condition is inherited in an autosomal recessive fashion and is caused by mutations in either the ITGA2B or ITGB3 genes.[1]
Last updated: 9/13/2011

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Prolonged bleeding time 0003010
Spontaneous, recurrent epistaxis
Recurring nosebleed
Spontaneous, recurrent nosebleed
[ more ]
0004406
30%-79% of people have these symptoms
Bruising susceptibility
Bruise easily
Easy bruisability
Easy bruising
[ more ]
0000978
Gingival bleeding
Bleeding gums
0000225
Prolonged bleeding after surgery
Excessive bleeding during surgery
Protracted bleeding after surgery
[ more ]
0004846
Prolonged bleeding following circumcision 0030137
5%-29% of people have these symptoms
Ecchymosis 0031364
Gastrointestinal hemorrhage
Gastrointestinal bleeding
0002239
Macroscopic hematuria
Bloody urine
0012587
Menometrorrhagia 0400008
Menorrhagia
Abnormally heavy bleeding during menstruation
0000132
Spontaneous hematomas 0007420
1%-4% of people have these symptoms
Impaired ristocetin-induced platelet aggregation 0011871
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance 0000007
Decreased platelet glycoprotein IIb-IIIa 0001975
Epistaxis
Bloody nose
Frequent nosebleeds
Nose bleed
Nose bleeding
Nosebleed
[ more ]
0000421
Impaired clot retraction 0031126
Impaired platelet aggregation 0003540
Intracranial hemorrhage
Bleeding within the skull
0002170
Purpura
Red or purple spots on the skin
0000979
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

FDA-Approved Treatments

The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.

  • Coagulation Factor VIIa (Recombinant) (Brand name: NovoSeven RT) - Manufactured by Novo Nordisk, Inc.
    FDA-approved indication: March 2005, NovoSeven RT was approved for the prevention of bleeding in surgical interventions or invasive procedures in hemophilia A or B patients with inhibitors to Factor VIII or Factor IX. Previously in March 1999, NovoSeven RT was approved for the treatment of bleeding episodes in hemophilia A or B patients with inhibitors to Factor VIII or Factor IX. July 2014, NovoSeven RT was approved for the treatment of bleeding episodes and peri-operative management in adults and children with Glanzmann's thrombasthenia with refractoriness to platelet transfusions, with or without antibodies to platelets.
    National Library of Medicine Drug Information Portal

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Glanzmann thrombasthenia. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Glanzmann thrombasthenia. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Glanzmann thrombasthenia. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. Glanzmann thrombasthenia. National Organization for Rare Disorders (NORD). 2009; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/156/viewAbstract. Accessed 9/13/2011.