Abstract
A young woman with a history of thrombocytopenia was treated for idiopathic thrombocytopenic purpura (ITP) with splenectomy, intravenous immunoglobulin, steroids and chemotherapeutic agents. The patient experienced hearing loss during childhood and, as a teenager, was diagnosed with hypertension and nephrotic-range proteinuria, which progressed to renal failure requiring dialysis. On presentation to our institution, her platelet count was 13×10(9) /L. Peripheral blood smear showed giant platelets and leucocyte inclusions. The presence of thrombocytopenia with giant platelets, leucocyte inclusions, renal failure and hearing loss raised the possibility of MYH9-related disorder (MYH9-RD). Genetic testing revealed a pathogenic mutation, c.2105G>A (p.Arg702His), confirming the diagnosis. Patients with MYH9-RD are frequently misdiagnosed with ITP and consequently receive futile and potentially toxic interventions. Considering MYH9-RD as a differential diagnosis in patients presenting with thrombocytopenia is important, especially when there is a history of early-onset renal failure, hearing loss, or cataracts.