title: Translocation (12;21) followed by insertion of chromosome 3 material in the derivative chromosome 12 in a case of childhood acute lymphoblastic leukemia.
abstract: We report a 2-year-old boy with B-cell acute lymphoblastic leukemia. Cytogenetic studies at diagnosis with R-banding showed a 46,XY,ins(12;3)(p13;q?21q?22)/46,XY karyotype. Fluorescence in situ hybridization with TEL/AML1 probes and chromosome paints revealed complex rearrangements. The TEL/AML1 fusion gene was located on the derivative chromosome 21 but a segment of the long arm of a chromosome 3 was inserted between the proximal part of the short arm of the derivative chromosome 12 and the reciprocal part of the AML1 gene. This is consistent with an insertion of chromosome 3 into chromosome 12 after the t(12;21) took place, therefore indicating a probable secondary event due to clonal evolution.
authors.affiliation: Service d'Hématologie Clinique, Institut d'Hématologie et de Cancérologie, CHU Morvan, Brest, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Douet-Guilbert
authors.forename: Frédéric
authors.initials: F
authors.lastname: Morel
authors.forename: Marie-Josée
authors.initials: MJ
authors.lastname: Le Bris
authors.forename: Angèle
authors.initials: A
authors.lastname: Herry
authors.forename: Geneviève
authors.initials: G
authors.lastname: Le Calvez
authors.forename: Véronique
authors.initials: V
authors.lastname: Marion
authors.forename: Christian
authors.initials: C
authors.lastname: Berthou
authors.forename: Marc
authors.initials: M
authors.lastname: De Braekeleer
mesh_terms: D002675:Child, Preschool; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D014178:Translocation, Genetic / Q000235:genetics*