A patient's peripheral blood smear reveals many giant platelets. All platelet function tests show normal aggregation with the exception of ristocetin. From what is the patient most likely suffering?

Question

Quizplus · Accepted Answer

The giant platelets and abnormal ristocetin-induced platelet aggregation suggest a problem with the platelet glycoprotein Ib-IX-V complex, which is responsible for binding to von Willebrand factor. Bernard-Soulier syndrome is a rare inherited disorder characterized by a deficiency or dysfunction of this complex, leading to impaired platelet adhesion and clot formation. Glanzmann's thrombasthenia is a rare inherited disorder characterized by a deficiency of the platelet glycoprotein IIb/IIIa complex, leading to impaired platelet aggregation. Storage pool disease is a collective term for a group of inherited disorders characterized by defects in granules that store various substances important for platelet function. Wiskott-Aldrich syndrome is a rare X-linked disorder characterized by a triad of thrombocytopenia, eczema, and recurrent infections, and is caused by mutations in the WAS gene.

A Patient's Peripheral Blood Smear Reveals Many Giant Platelets