title: Tetrasomy 21 as a sole acquired abnormality without GATA1 gene mutation in pediatric acute megakaryoblastic leukemia: a case report and review of the literature.
abstract: We report a case of pediatric acute megakaryocytic leukemia (AMKL) showing 48,XX,+21,+21 as a sole acquired cytogenetic abnormality without the mutation of GATA1 gene. A physical examination showed a phenotypically normal female. Bone marrow findings showed diffuse infiltration of leukemic blasts having scanty cytoplasm with budding blebs and prominent nucleoli, which were negative for myeloperoxide (MPO) stain, Sudan black B stain and periodic acid-Schiff stain. Immunophenotyping of leukemic cells revealed positive expression of CD34, CD13, CD33, CD117, CD41, CD61, CD7 and negative expression of TdT, anti-MPO, CD64, CD56, CD2, CD3, CD5, CD10, CD19, CD20 and CD22. A fluorescence in situ hybridization analysis showed four distinct AML1 signals in 284 of 300 interphase nuclei. The entire six exons of the GATA1 gene (7757bp) were directly sequenced. We could not find any mutations, including known polymorphisms, which are known to be involved in transient myeloproliferative disorder and acute megakaryocytic leukemia of Down syndrome. After achieving complete remission, the tetrasomy 21 disappeared.
authors: Department of Laboratory Medicine, Chonnam National University Hwasun Hospital, Hwasun, South Korea. mgshin@chonnam.ac.kr
authors: Myung-Geun
authors: MG
authors: Shin
authors: Hyun-Woo
authors: HW
authors: Choi
authors: Hye-Ran
authors: HR
authors: Kim
authors: Mi-Ji
authors: MJ
authors: Kim
authors: Hee-Jo
authors: HJ
authors: Baek
authors: Dong-Kyun
authors: DK
authors: Han
authors: Hoon
authors: H
authors: Kook
authors: Tai-Ju
authors: TJ
authors: Hwang
authors: Hyoung-Joon
authors: HJ
authors: Kim
authors: Soo-Hyun
authors: SH
authors: Kim
authors: Jong-Hee
authors: JH
authors: Shin
authors: Soon-Pal
authors: SP
authors: Suh
authors: Dong-Wook
authors: DW
authors: Ryang
mesh_terms: D000782:Aneuploidy; D002675:Child, Preschool; D002891:Chromosomes, Human, Pair 21; D020732:Cytogenetic Analysis; D005260:Female; D050982:GATA1 Transcription Factor / Q000235:genetics*; D006801:Humans; D007947:Leukemia, Megakaryoblastic, Acute / Q000175:diagnosis / Q000235:genetics*; D009154:Mutation
chemical_list: D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human