MYH9-RD is a collection of disorders caused by mutations in the MYH9 gene, encoding the Myosin9 subunit of Myosin2A, which includes May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome. The gene discussed is MYH9; the disease is macrothrombocytopenia and granulocyte inclusions with or without nephritis or sensorineural hearing loss.