Unusual location of BCR-ABL1 fusion sequences in a chronic myeloid leukemia patient

Hematology. 2012 Nov;17(6):321-4. doi: 10.1179/1607845412Y.0000000012. Epub 2012 Sep 14.

Abstract

We describe a case of a chronic myeloid leukemia patient displaying the chimeric BCR-ABL1 gene on 12p11. Chromosome analysis revealed complex chromosome aberration involving chromosomes 9, 12, and 22. Fluorescence in situ hybridization revealed an unusual signal pattern revealing the BCR-ABL1 fusion signal on chromosome 12, while no reciprocal ABL1-BCR fusion was detected on der(9) chromosome. The relocation of BCR-ABL1 fusion sequences to 12p11 site in our patient represents a rare type of variant translocation, as in almost all patients the chimeric BCR-ABL1 gene is located on der(22) chromosome. Our case illustrates the challenge of recognizing a complex pattern of cytogenetic aberrations that occur with variant t(9;22) and may add further information about clinical significance of unusual variant Ph rearrangements in CML patients receiving tyrosine kinase inhibitor treatment.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Chromosome Banding
  • Chromosomes, Human, Pair 12*
  • Fusion Proteins, bcr-abl / genetics*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / diagnosis
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics*
  • Male
  • Translocation, Genetic*

Substances

  • Fusion Proteins, bcr-abl