A unique three-way Philadelphia chromosome variant t(4;9;22)(q21;q34;q11.2) in a newly diagnosed patient with chronic phase chronic myeloid leukemia: a case report and review of the literature

Autor: Masakazu Yamamoto, Kana Nanjo, Ryo Sato, John M. Magenau, Keiko Aizawa, Masashi Hosokawa, Tomomi Toubai, Yuka Torii, Akane Yamada, Kenichi Ishizawa, Ryan A. Wilcox, Masahito Himuro, Satoshi Ito
Rok vydání: 2021
Předmět:
Zdroj: Journal of Medical Case Reports, Vol 15, Iss 1, Pp 1-6 (2021)
Journal of Medical Case Reports
ISSN: 1752-1947
DOI: 10.1186/s13256-021-02885-4
Popis: Background Chronic myeloid leukemia is a hematologic malignancy associated with the fusion of two genes: BCR and ABL1. This fusion results from a translocation between chromosomes 9 and 22, which is called the Philadelphia chromosome. Although the Philadelphia chromosome is present in more than 90% of patients with chronic myeloid leukemia, 5–8% of patients with chronic myeloid leukemia show complex variant translocations. Herein, we report a unique case of a three-way translocation variant in chronic phase chronic myeloid leukemia. Case presentation A 40-year-old Asian male who presented with leukocytosis was diagnosed with chronic phase chronic myeloid leukemia. Cytogenetic karyotyping analysis showed 46,XY,t(4;9;22)(q21;q34;q11.2). He was treated with bosutinib and then changed to dasatinib because of intolerance, and MR4.5 (BCR-ABL/ABL ≦ 0.0032%, international scale) was achieved after 17 months of continuous treatment. Conclusion This was the 14th case of t(4;9;22), in particular, a new variant Ph translocation involved in chromosome 4q21 and the first successful case treated with tyrosine kinase inhibitors in the world. We summarize previous case reports regarding three-way variant chromosome translocation, t(4;9;22) and discuss how this rare translocation is linked to prognosis.
Databáze: OpenAIRE
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