Diagnostic delay of MYH9‐related disorder in Japan

• Published in: British journal of haematology Vol. 204; no. 6; pp. 2400 - 2404
• Main Authors: Sakamoto, Atsushi, Uchiyama, Toru, Kaname, Tadashi, Iguchi, Akihiro, Ohara, Osamu, Ishimura, Masataka, Onum, Masaei, Kunishima, Shinji, Ishiguro, Akira
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.06.2024
• Subjects: Adolescent; Adult; Age Factors; Aged; Child; Child, Preschool; Delayed Diagnosis - statistics & numerical data; Diagnosis; Diagnostic Errors; Döhle‐like body; Female; Genetic Testing - statistics & numerical data; giant platelet; Hearing Loss, Sensorineural - blood; Hearing Loss, Sensorineural - congenital; Hearing Loss, Sensorineural - diagnosis; Hearing Loss, Sensorineural - genetics; Humans; Idiopathic thrombocytopenic purpura; Inclusion bodies; Infant; Infant, Newborn; Japan; Leukocytes (granulocytic); macroplatelet; macrothrombocytopenia; Male; Mean Platelet Volume; Middle Aged; Mutation; MYH9‐related disorder; Myosin Heavy Chains - genetics; Prospective Studies; Purpura, Thrombocytopenic, Idiopathic - diagnosis; Purpura, Thrombocytopenic, Idiopathic - genetics; Purpura, Thrombocytopenic, Idiopathic - immunology; Registries - statistics & numerical data; splenectomy; Thrombocytopenia - blood; Thrombocytopenia - congenital; Thrombocytopenia - diagnosis; Thrombocytopenia - genetics; Young Adult; Japan; giant platelet; MYH9‐related disorder; Döhle‐like body; macrothrombocytopenia; macroplatelet; splenectomy
• ISSN: 0007-1048; 1365-2141; 1365-2141
• DOI: 10.1111/bjh.19484

Summary MYH9‐related disorder (MYH9‐RD) is characterized by congenital macrothrombocytopenia and granulocyte inclusion bodies. MYH9‐RD is often misdiagnosed as chronic immune thrombocytopenia. In this study, we investigated age at definitive diagnosis and indicative thrombocytopenia in 41 patients with MYH9‐RD from the congenital thrombocytopenia registry in Japan. Our cohort comprises 54.8% adults over 18 years at confirmed diagnosis. We found a significant difference (p < 0.0001) between the median age at definitive diagnosis of 25.0 years and for indicative thrombocytopenia it was 9.0 years. Our findings strongly suggest diagnostic delay of MYH9‐RD in Japan. Our registry system will continue to contribute to this issue.