title: Isodicentric/pseudoisodicentric chromosome 21 amplification in four cases of acute myelocytic leukemia or myelodysplasia.
abstract: The bone marrow karyotypes of three patients with acute myelocytic leukemia (AML) or myelodysplastic syndrome (MDS) were studied at diagnosis and revealed, multiple copies of the same chromosomal anomaly, considered as psu idic(21)(q22) associated with other rearrangement(s). The karyotype of a fourth patient with MDS in transformation showed one copy of a dicentric marker presumably derived from a similar psu idic(21) by (tandem?) interstitial amplification of part of its structure, resembling a "homogeneous staining region", and described as der(21)psu idic(21)(q22)hsr(21)(q22). This rearrangement, previously described in isolated cases only, might be considered as recurrent in AML/MDS and associated with an unfavorable prognosis. It is most probably a secondary change, because it was never observed as sole abnormality and the main association, as for trisomy 21, was with del(5q). In the four cases, the number of partial supernumerary segmental 21pter-->21q22 copies, ranged from 2 to 10. The AML1 gene did not appear to be the common target of this amplification because this locus had been lost by the psu idic(21) in one patient
authors.affiliation: Laboratoire de Cytogénétique Onco-Hématologique, Hôpital Hôtel-Dieu, Paris, France. franck.viguie@htd.ap-hop-paris.fr
authors.forename: Franck
authors.initials: F
authors.lastname: Viguié
authors.forename: Azzedine
authors.initials: A
authors.lastname: Aboura
authors.forename: Didier
authors.initials: D
authors.lastname: Bouscary
authors.forename: Martine
authors.initials: M
authors.lastname: Guesnu
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Baumelou
authors.forename: François
authors.initials: F
authors.lastname: Dreyfus
authors.forename: Nicole
authors.initials: N
authors.lastname: Casadevall
authors.forename: Gérard
authors.initials: G
authors.lastname: Tachdjian
mesh_terms: D000368:Aged; D002869:Chromosome Aberrations; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins / Q000235:genetics; D005784:Gene Amplification; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000235:genetics*; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors / Q000235:genetics
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C493728:RUNX1 protein, human; D014157:Transcription Factors