Glanzmann Thrombasthenia

Genetic platelet disorder resulting in blood clotting disorder and hemorrhage. Life-threatening condition under stress (e.g., surgery, anesthesia).

Athrombocytopenic Purpura; Congenital Hemorrhagic Thrombocytic Dystrophy; Glanzmann Syndrome; Glanzmann-Nägeli Syndrome; Glycoprotein IIb (GPIIb/III) Complex Deficiency; Hemorrhagic Thrombasthenia; Hereditary Thrombasthenia; Hereditary Thrombocytopenic Purpura; Nägeli Syndrome II; Platelet Fibrinogen Receptor Deficiency; Platelet Glycoprotein IIb/III Deficiency; Révol Syndrome; Thrombasthenia; Thrombocytasthenia; Thrombocytopathic Purpura.

Eduard Glanzmann (1887-1959) was a Swiss pediatrician, Otto Nägeli (1871-1938) was a Swiss hematologist.

Rare. Approximately 200 cases reported.

Autosomal recessive disorder in one of two genes of chromosome 17, either GPIIb (or integrin αIIb) or GPIIIa (or integrin αIIbβ3), where GP indicates glycoprotein. Genetic mutations split equally between GPIIb and GPIIIa. Some cases are suspected to be transmitted as an autosomal dominant trait.

In platelets, GPIIb and GPIIIa are joined together as a dimer (referred to as GPIIb/IIIa). Once activated, GPIIb/IIIa binds to one end of fibrinogen (and/or von Willebrand factor), while another platelet, with its own GPIIb/IIIa, can bind to the other extremity of the fibrinogen, thus leading to a large aggregation of bound platelets (so-called white blood clot). In patients with Glanzmann thrombasthenia, GPIIb/IIIa is defective and platelets cannot aggregate; no blood clot is formed and bleeding does not stop.

Normal to increased platelet count, giant platelets, absent platelet surface thrombosthenin, prolonged bleeding time, poor clot retraction, and absent platelet aggregation. Adenosine diphosphate-induced platelet aggregation does not occur.

Bleeding diathesis, petechiae, anemia. Two forms described: type I (severely affected patients, especially girls at time of menarche) and type II (mild form).

Check CBC. Ensure platelet availability. Check for platelet antibodies.

Avoid central neuraxial anesthetics. Anticipate need for platelet transfusion. Platelet transfusions must be restricted to serious bleeding because antibodies against platelets can develop (and would compromise the vital prognosis in case of further bleeding). Postoperative bleeding may be severe. Perioperative treatment with recombinant FVIIa supplements has proven to be safe and efficient.

Avoid use of antiplatelet drugs such as acetylsalicylic acid.

Bernard-Soulier Syndrome: Autosomal recessive bleeding disorder with low platelet count and bleeding out of proportion to the reduced platelet count.

Wiskott-Aldrich Syndrome: X-linked recessive disorder with altered platelets, bleeding disorder, and susceptibility to infections as a consequence of Band T-cell immunodeficiencies.