From delayed recognition to long-term disease control: Eltrombopag in severe MYH9-related disease

Variants in MYH9, which encodes the heavy chain isoform A of non-muscle myosin class II, cause MYH9-related disease (MYH9-RD), a rare inherited disorder characterized by congenital macrothrombocytopenia and several extra-hematologic manifestations. Its phenotypic heterogeneity may hinder prompt recognition or lead to misdiagnosis. We report the case of a 52-year-old man with severe thrombocytopenia and hemorrhagic manifestations associated with bilateral sensorineural hearing loss, cataracts, and end-stage kidney disease requiring kidney transplantation. Eltrombopag, a thrombopoietin receptor agonist, was administered off-label, resulting in a clinically significant increase in platelet count, subsequent normalization during follow-up, and improvement in the bleeding profile. This case suggests that eltrombopag may represent a potentially effective long-term therapeutic option for patients with severe symptomatic MYH9-RD.