Skip to main content

Saturn Medic

Clinical Subject Page

Glanzmann Thrombasthenia (GT)

Glanzmann thrombasthenia is a rare inherited platelet aggregation disorder caused by deficiency or dysfunction of the platelet GPIIb/IIIa receptor, resulting in defective platelet aggregation and mucocutaneous bleeding.

Also called

Qualitative platelet defects

ICD-10

D69.1

Specialty

Hematology

Onset

Chronic

Reviewed

August 2026

On This Page

Overview

• Rare autosomal recessive inherited platelet function disorder.
• Caused by deficiency or dysfunction of the GPIIb/IIIa (integrin aIIbb3) receptor.
• Platelet count and morphology are usually normal.
• Results in defective platelet aggregation with normal coagulation factors.

Etiology & Risk Factors

Glanzmann Thrombasthenia (GT) is a rare inherited platelet function disorder caused by a deficiency or dysfunction of the platelet glycoprotein IIb/IIIa (GPIIb/IIIa) receptor, which is essential for platelet aggregation.

It is caused by mutations in the ITGA2B or ITGB3 genes → defective or absent GPIIb/IIIa receptor → impaired binding of fibrinogen → failure of platelet aggregation → prolonged mucocutaneous bleeding.

Inheritance

  • Autosomal recessive
  • Usually requires pathogenic variants in both copies of the responsible gene.
  • Consanguinity increases the likelihood of the disorder.


    Risk Factors

    Glanzmann Thrombasthenia (GT) is genetic, so there are no acquired lifestyle risk factors.

    Important risk factors include:

    • Positive family history
    • Consanguineous parents
    • Family history of unexplained bleeding
    • Previous affected siblings
    • Belonging to populations with a higher prevalence of inherited disorders due to consanguinity

Pathophysiology

• Defective GPIIb/IIIa receptor prevents fibrinogen-mediated platelet aggregation.
• Primary hemostasis is impaired despite normal coagulation factor activity.
• Leads to prolonged mucocutaneous bleeding.

Clinical Presentation

Mucocutaneous bleeding: Petechiae, purpura, easy bruising, epistaxis, gingival bleeding,
menorrhagia, prolonged bleeding after trauma, surgery, or dental procedures

History Taking

-Recurrent epistaxis
-Easy bruising
-Gingival bleeding
-Heavy menstrual bleeding
-Bleeding after
-Dental extraction or surgery childhood —Onset of symptoms
-Family history of bleeding disorders.

Physical Examination

Petechiae

Purpura,

Ecchymoses

Mucosal bleeding

and signs of anemia if chronic blood loss is present.

Investigations

CBC: Platelet count normal.
Peripheral blood smear: Normal platelet morphology.
Coagulation profile: PT normal, aPTT normal.
Platelet function testing: Abnormal platelet aggregation confirms the diagnosis.
Advanced platelet function testing: Used to identify inherited platelet function disorders such as
Glanzmann thrombasthenia.

Diagnosis

Diagnosis is based on:

Compatible bleeding history
Normal platelet count
Normal platelet morphology

Normal PT and aPTT
Abnormal platelet aggregation testing.

Home / Home / Clinical Cases / Hematology System Clinical Cases / Glanzmann Thrombasthenia (GT)
Related Topics

Management

General measures: Hematology referral and avoidance of medications that impair platelet function
(e.g., aspirin and NSAIDs).

During bleeding episodes: Supportive hemostatic management and blood product transfusion when
clinically indicated.

Perioperative care: Plan bleeding management with a hematologist before surgery or invasive
procedures.

Complications

  • Recurrent mucocutaneous
  • bleeding, excessive postoperative bleeding
  • iron-deficiency anemia
    due to chronic blood loss.

Prognosis

Most patients have a normal life expectancy. Prognosis depends on bleeding severity and
appropriate supportive management

Key Points / Clinical Pearls

• Rare autosomal recessive platelet function disorder.
• Defect of the GPIIb/IIIa receptor.
• Causes impaired platelet aggregation.
• Presents with mucocutaneous bleeding.
• Platelet count is normal.
• Peripheral smear shows normal platelets.
• PT and aPTT are normal.
• Abnormal platelet aggregation testing confirms the diagnosis.
• Management is mainly supportive with hematology follow-up and avoidance of platelet-inhibiting
medications