MYH9 disorder: Identification and a novel mutation in patients with macrothrombocytopenia

• Main Authors: Rungrote Natesirinilkul, Darintr Sosothikul, Patcharee Komwilaisak, Bunchoo Pongtanakul, Nattee Narkbunnum, Najwa Yudhasompop, Pimsiri Mekjarusgool, Pimjai Niparuck, Kochawan Boonyawat, Shinji Kunishima, Nongnuch Sirachainan, Somjai Kanjanapongkul, Thirachit Chotsampancharoen, Chanchai Trivaree, Siranee Wongruangsri, Pacharapan Surapolchai, Sumonmaln Klamchuen, Saranya Busakornruangrat, Kittima Kanchanakamhaeng, Nattaporntira Phalakornkul
• Other Authors: Siriraj Hospital
• Format: Article
• Published: 2022
• Subjects: Medicine
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/78048
• Institution: Mahidol University

The diagnosis of MYH9 disorder is guided by recognizing granulocyte Döhle body-like inclusion bodies and large/giant platelets in the peripheral blood smear. Immunofluorescence study of nonmuscle myosin heavy chain IIA is a sensitive screening method for diagnosis of MYH9 disorder. The diagnosis can then be confirmed by genetic analysis. A total of 67 patients with macrothrombocytopenia were included, of which 11 patients (16%), aged 4 months to 22 years, were ultimately diagnosed with MYH9 disorder. One novel mutation in exon 30 at c.4338T>C (p.F1446A) was detected. This mutation was associated with nonhematologic manifestations presenting in late adolescence with cataracts, hearing loss, and hematuria.