title: Detection of RBM15-MKL1 fusion was useful for diagnosis and monitoring of minimal residual disease in infant acute megakaryoblastic leukemia.
abstract: Acute megakaryocytic leukemia (AMKL) with t(1;22)(p13;q13) is a distinct category of myeloid leukemia by WHO classification and mainly reported in infants and young children. Accurate diagnosis of this type of AMKL can be difficult, because a subset of patients have a bone marrow (BM) blast percentage of less than 20% due to BM fibrosis. Therefore, it is possible that past studies have underestimated this type of AMKL. We present here the case of a 4-month-old female AMKL patient who was diagnosed by presence of the RBM15-MKL1 (OTT-MAL) fusion transcript by RT-PCR. In addition, we monitored RBM15-MKL1 fusion at several time points as a marker of minimal residual disease (MRD), and found that it was continuously negative after the first induction chemotherapy even by nested RT-PCR. Detection of the RBM15-MKL1 fusion transcript thus seems to be useful for accurate diagnosis of AMKL with t(1;22)(p13;q13). We recommend that the RBM15-MKL1 fusion transcript be analyzed for all suspected AMKL in infants and young children. Furthermore, monitoring of MRD using this fusion transcript would be useful in treatment of AMKL with t(1;22)(p13;q13).
authors.affiliation: Department of Pediatrics, Okayama University Hospital, Okayama 700-8558, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Takeda
authors.forename: Akira
authors.initials: A
authors.lastname: Shimada
authors.forename: Kazuko
authors.initials: K
authors.lastname: Hamamoto
authors.forename: Syuuji
authors.initials: S
authors.lastname: Yoshino
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nagai
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Fujii
authors.forename: Mutsuko
authors.initials: M
authors.lastname: Yamada
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Yuki
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Kanae
authors.initials: K
authors.lastname: Sakakibara
authors.forename: Megumi
authors.initials: M
authors.lastname: Oda
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Morishima
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D007947:Leukemia, Megakaryoblastic, Acute / Q000188:drug therapy* / Q000235:genetics*; D018365:Neoplasm, Residual / Q000188:drug therapy / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: C532421:OTT-MAL fusion protein, human; D015514:Oncogene Proteins, Fusion