The role of an accurate diagnosis of inherited thrombocytopenia as the basis for an effective treatment. A case of MYH9 syndrome treated with a TPO-RA

MYH9‐related platelet disorders (MYH9‐RDs) are autosomal‐dominant, syndromic thrombocytopenias caused by mutations of MYH9, the gene encoding for the non‐muscular myosin heavy chain IIA (NMMHC‐IIA). All affected individuals present congenital macrothrombocytopenia, giant platelets and NMMHC‐IIA inclusions in the cytoplasm of granulocytes. Most patients develop late‐onset, extra‐haematological manifestations, namely renal failure, sensorineural hearing loss, presenile cataract and elevation of liver enzymes; in some cases, the thrombocytopenia remains the only feature of the disease. The diagnosis is based on the detection of granulocyte inclusion bodies on blood smears, immunofluorescence analyses and/or the identification of a heterozygous pathogenic MYH9 variant.