Glanzmann thrombasthenia

Glanzmann thrombasthenia (GT), also known as Glanzmann disease or thrombasthenia of Glanzmann and Naegeli, is a rare inherited bleeding disorder caused by a deficiency or dysfunction of the platelet glycoprotein IIb/IIIa complex (integrin αIIbβ3). This glycoprotein complex is essential for platelet aggregation, the process by which platelets clump together to form a blood clot. Without functional GPIIb/IIIa, platelets cannot bind fibrinogen and aggregate properly, even though platelet counts remain normal. The disease primarily affects the hematologic system, leading to a lifelong tendency toward mucocutaneous bleeding. Key clinical features include purpura (easy bruising), epistaxis (nosebleeds), gingival (gum) bleeding, menorrhagia (heavy menstrual bleeding in women), and prolonged bleeding following trauma, surgery, or dental procedures. Gastrointestinal bleeding may also occur. Symptoms typically present in the neonatal period or early childhood, often with petechiae or prolonged bleeding from the umbilical stump. The severity of bleeding is variable, even among affected members of the same family, and can range from mild to life-threatening hemorrhage. Glanzmann thrombasthenia is classified into three types based on the level of GPIIb/IIIa expression: Type I (less than 5% of normal levels), Type II (5–20% of normal levels), and variant forms (normal or near-normal levels but dysfunctional protein). Treatment is primarily supportive and includes local hemostatic measures, antifibrinolytic agents (such as tranexamic acid), platelet transfusions for severe or uncontrolled bleeding, and recombinant activated factor VII (rFVIIa) as an alternative when platelet transfusions are ineffective or when patients develop anti-platelet antibodies. Hormonal therapy may be used to manage menorrhagia. Hematopoietic stem cell transplantation has been performed in severe cases, and gene therapy is under investigation. Patients are advised to avoid antiplatelet medications such as aspirin and NSAIDs.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Glanzmann thrombasthenia