A rare autosomal dominant genetic disorder characterized by giant platelets, thrombocytopenia, and leukocytes with Dohle body inclusions. Caused by abnormalities in gene MYH9. Signs and symptoms include prolonged bleeding time, purpura, epistaxis, gingival hemorrhage, intracranial bleeding, menorrhagia, and easy bruising. Patients can be asymptomatic, or symptoms may present at birth. Males and females are equally affected. Treatment is only required during episodes of substantial bleeding. Precautions in case of excess bleeding should be taken with pregnant patients and during surgery or dental work. Closely related to Sebastian syndrome, Fechtner syndrome, and Epstein syndrome.