Abstract
May-Hegglin anomaly (MHA) is one of the inherited platelet disorders characterized by thrombocytopenia, giant platelets and Döhle body-like leukocyte inclusions in peripheral blood. Recently gene mutations in MHA and MHA-related diseases have been identified. We report a 10-day-old male infant with thrombocytopenia, which was not improved with high-dose γ-globulin administration or platelet transfusion. When he was referred to our hospital bleeding tendency was not seen. There were giant platelets in peripheral blood and small immature megakaryocytes in bone marrow. The function of platelets and bleeding time were normal. Anti-platelet antibodies were not detected. Giant platelets made the dissociation of platelet count between microscopic examination and blood cell counter (Coulter model JT). We suspected inherited thrombocytopenia including MHA. It was diagnosed as MYH9 disorder with the gene analysis of MYH9 (287 ; C → T). The patient has been well without any further treatment. In conclusion, it is important to check the smear for the differential diagnosis of inherited platelet disorders in the case of thrombocytopenia without bleeding tendencies.
