Validation of an interphase fluorescence in situ hybridization approach for the detection of MLL gene rearrangements and of the MLL/AF9 fusion in acute myeloid leukemia

Haematologica. 2006 Mar;91(3):381-5. Epub 2006 Feb 17.

Abstract

To validate a 2-step FISH assay for the identification of the t(9;11)(p22;q23), 96 acute myeloid leukemias were studied by cytogenetic analysis, FISH and molecular biology. After a first FISH step using an MLL probe, 24/27 cases with 11q23 break showed MLL rearrangement. Southern blotting confirmed FISH data. In the second step, 24 cases with MLL rearrangement were studied using MLL and AF9 probes: 17/18 cases with t(9;11) showed MLL/AF9 fusion. In 6 patients with 11q23/MLL rearrangements other than t(9;11), FISH confirmed MLL involvement and excluded AF9 involvement. This is a reliable method for the identification of MLL/AF9 fusion in interphase cells, allowing for a reclassification of cases with suboptimal chromosome morphology. The frequency of deletion surrounding MLL and AF9 breakpoint is low.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Gene Rearrangement / genetics*
  • Humans
  • In Situ Hybridization, Fluorescence / methods*
  • In Situ Hybridization, Fluorescence / standards
  • Interphase / genetics*
  • Leukemia, Myeloid, Acute / genetics*
  • Leukemia, Myeloid, Acute / metabolism
  • Leukemia, Myeloid, Acute / pathology
  • Myeloid-Lymphoid Leukemia Protein / genetics*
  • Nuclear Proteins / genetics*
  • Oncogene Proteins, Fusion / genetics*

Substances

  • MLL-AF9 fusion protein, human
  • MLLT3 protein, human
  • Nuclear Proteins
  • Oncogene Proteins, Fusion
  • Myeloid-Lymphoid Leukemia Protein