Glanzmann’s Thrombasthenia

Also known as: Glanzmann Thrombasthenia


Glanzmann’s thrombasthenia (GT) is a rare genetic bleeding disorder affecting the small cell fragments in the blood called platelets. Platelets are important because after injury they are the first blood components to form the plug which stops bleeding (the haemostatic plug).


Last reviewed April 2017 by Professor M Laffan, Professor of Haemostasis and Thrombosis and Honorary Consultant in Haematology, Imperial College School of Medicine, London, UK.

Although great care has been taken in the compilation and preparation of all entries to ensure accuracy, we cannot accept responsibility for any errors or omissions. Any medical information is provided is for education/information purposes and is not designed to replace medical advice by a qualified medical professional.

What are the symptoms?

Easy bruising is often noticed early and the diagnosis is usually made by the age of five years. The commonest problems are easy bruising, nose bleeds, heavy periods and gum bleeding. Prolonged bleeding has been reported after shedding of baby teeth and bleeding is of course prolonged after trauma and surgery.

Not all people with GT are affected to the same degree. Some people are severely affected, while others less so and have infrequent bleeding.

Overall, whilst bleeding after trauma or surgery may be severe, problems from spontaneous bleeding in day-to-day life are often mild. Affected women may have problems with excessive bleeding during their period.

What are the causes?

In people with GT, a particular protein (called IIb IIIa) is either missing from the platelets or does not work properly. The result is that the platelets cannot stick together adequately to form the haemostatic plug and bleeding is not stopped even from minor injuries.

How is it diagnosed?

If the results of preliminary tests and the bleeding pattern suggest GT then specialised tests on an ordinary blood sample are required. DNA testing may also be helpful.

How is it treated?

Episodes of bleeding can be treated in a number of ways depending on severity and urgency. Tablets or mouthwash of tranexamic acid may help by stabilising the clot. Bleeding will usually be arrested by transfusion of normal donor platelets. Sometimes an activated clotting factor called Factor VIIa (seven ‘a’) may be used.  

Bone marrow transplantation is the only treatment that offers a cure. This is a procedure that involves replacing patient bone marrow with healthy bone marrow stem cells, including platelets. However, this is generally considered more hazardous than the condition, except when bleeding is very severe. Nonetheless, this has successfully been performed in a number of cases.

Affected women often need hormonal treatment to reduce or suppress their periods. The oral contraceptive pill may be sufficient. Many patients, particularly women, become iron deficient as a result of frequent minor blood loss and regular iron supplements may be required.

Pregnancy in women affected by GT can be extremely hazardous, not only for the patient but for the child as well. Advice should be sought from a haematologist.

Drugs such as aspirin and ibuprofen (Nurofen, Cuprofen), which also inhibit platelet function should be avoided. Paracetamol is a useful alternative but there are others, contact your doctor for advice.

Inheritance patterns and prenatal diagnosis

Inheritance patterns
Inheritance is autosomal recessive. Therefore carriers, (those that carry one copy of the mutated gene causing GT), are unaffected and it is more common in children whose parents are related.

Prenatal diagnosis
As the genetic basis for GT is known, identification of affected pregnancies can be performed at an early stage. Carriers can be identified by testing their platelets or by DNA testing.

Is there support?

Glanzmann’s Thrombasthenia Contact Group

Tel: 0161 368 0219

This Group was established in 1990. It provides information and support to anyone affected by Glanzmann’s Thrombasthenia in the UK, and has close links with the Glanzmann’s Research Foundation in the USA. It has an active Facebook group. 

Group details last updated December 2014.

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