Publication:

MLL translocations with concurrent 3' deletions: interpretation of FISH results (2004)

Author(s): Barber KE, Ford AM, Harris RL, Harrison CJ, Moorman AV

  • : MLL translocations with concurrent 3' deletions: interpretation of FISH results

Abstract: Rearrangements involving the MLL gene at 11q23 occur in a clinically relevant subgroup of patients with acute lymphoblastic leukemia (ALL) at all ages, and therefore their accurate identification at diagnosis is important. It has become commonplace to screen ALL patients for rearrangements of MLL using a dual-color fluorescence in situ hybridization (FISH) assay. We report on 12 ALL patients with an unusual FISH result consisting of the following signal pattern: one 5' green, no 3' red, and one/two fusion signals. This configuration is consistent with a MLL translocation and simultaneous deletion of 3' MLL-a well-established phenomenon-which has been interpreted as a positive result. G-banded and complementary metaphase FISH analyses confirmed an 11q23/MLL translocation in 8 of the 12 cases, whereas in one case, the identification of a del(11)(q23) was restricted to G-banded analysis only. In three cases, an MLL rearrangement was excluded by extensive FISH analysis and/or Southern blotting. In conclusion, the loss of the 3' MLL signal should not be assumed to be the result of a concurrent translocation and deletion event, and such aberrant FISH signal patterns should be investigated further by alternative methods for determining their MLL status.

Notes: Journal Article Research Support, Non-U.S. Gov't United States

  • Short Title: MLL translocations with concurrent 3' deletions: interpretation of FISH results
  • Alternate Journal: Genes, chromosomes & cancer
  • Date: 11-08-2004
  • Journal: Genes, Chromosomes and Cancer
  • Volume: 41
  • Issue: 3
  • Pages: 266-271
  • Publication type: Article
  • Bibliographic status: Published

Keywords: Blotting, Southern Child Child, Preschool Chromosome Banding Chromosomes, Human, Pair 11 DNA-Binding Proteins/*genetics Female *Gene Deletion Humans In Situ Hybridization, Fluorescence Infant Karyotyping Male Metaphase Myeloid-Lymphoid Leukemia Protein Precursor Cell Lymphoblastic Leukemia-Lymphoma/*genetics Proto-Oncogenes/*genetics Statistics as Topic/methods Transcription Factors/*genetics *Translocation, Genetic

Staff

Professor Anthony Moorman
Professor of Genetic Epidemiology