A BCR-JAK2 fusion gene as the result of a t(9;22)(p24;q11.2) translocation in a patient with a clinically typical chronic myeloid leukemia

Genes Chromosomes Cancer. 2005 Nov;44(3):329-33. doi: 10.1002/gcc.20235.


Chronic myeloid leukemia (CML) is characterized by the presence of a t(9;22)(q34;q11.2), which leads to the well-known BCR-ABL1 fusion protein. We describe a patient who was diagnosed clinically with a typical CML but on cytogenetic analysis was found to have a t(9;22)(p24;q11.2). Chromosomal fluorescence in situ hybridization showed that the BCR gene locus spanned the breakpoint at band 22q11.2 but that the ABL1 gene was not rearranged. By means of a candidate gene approach, the JAK2 gene, at 9p24, was identified as the fusion partner of BCR in this case. The BCR-JAK2 fusion protein contains the coiled-coil dimerization domain of BCR and the protein tyrosine kinase domain (JH1) of JAK2. The patient's disease did not respond to Imatinib, and this unresponsiveness was most likely a result of the BCR-JAK2 fusion protein.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Antineoplastic Agents / therapeutic use
  • Benzamides
  • Chromosomes, Human, Pair 22 / genetics*
  • Chromosomes, Human, Pair 9 / genetics*
  • Female
  • Humans
  • Imatinib Mesylate
  • In Situ Hybridization, Fluorescence
  • Janus Kinase 2
  • Karyotyping
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics*
  • Middle Aged
  • Oncogene Proteins, Fusion / genetics*
  • Piperazines / therapeutic use
  • Protein-Tyrosine Kinases / genetics*
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins c-bcr / genetics*
  • Pyrimidines / therapeutic use
  • Translocation, Genetic / genetics*


  • Antineoplastic Agents
  • Benzamides
  • Oncogene Proteins, Fusion
  • Piperazines
  • Proto-Oncogene Proteins
  • Pyrimidines
  • Imatinib Mesylate
  • Protein-Tyrosine Kinases
  • JAK2 protein, human
  • Janus Kinase 2
  • BCR protein, human
  • Proto-Oncogene Proteins c-bcr