MYH9-RD encompasses four syndromes that have been considered for many years as distinct disorders, May-Hegglin Anomaly (MHA, MIM 155100), Sebastian syndrome (SBS, MIM 605249), Fechtner syndrome (FTNS, MIM 153640), and Epstein syndrome (EPTS, MIM 153650). The gene discussed is MYH9; the disease is macrothrombocytopenia and granulocyte inclusions with or without nephritis or sensorineural hearing loss.