Philadelphia chromosomal breakpoints are clustered within a limited region, bcr, on chromosome 22

Cell. 1984 Jan;36(1):93-9. doi: 10.1016/0092-8674(84)90077-1.


We have identified and molecularly cloned 46 kb of human DNA from chromosome 22 using a probe specific for the Philadelphia (Ph') translocation breakpoint domain of one chronic myelocytic leukemia (CML) patient. The DNAs of 19 CML patients were examined for rearrangements on chromosome 22 with probes isolated from this cloned region. In 17 patients, chromosomal breakpoints were found within a limited region of up to 5.8 kb, for which we propose the term "breakpoint cluster region" (bcr). The two patients having no rearrangements within bcr lacked the Ph' chromosome. The highly specific presence of a chromosomal breakpoint within bcr in Ph'-positive CML patients strongly suggests the involvement of bcr in this type of leukemia.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins*
  • Base Sequence
  • Chromosomes, Human, 21-22 and Y*
  • Cloning, Molecular
  • DNA Restriction Enzymes
  • DNA, Neoplasm
  • Deoxyribonuclease BamHI
  • Deoxyribonuclease HindIII
  • Deoxyribonucleases, Type II Site-Specific*
  • Humans
  • Leukemia, Myeloid / genetics*
  • Nucleic Acid Hybridization
  • Translocation, Genetic*


  • Bacterial Proteins
  • DNA, Neoplasm
  • DNA Restriction Enzymes
  • Deoxyribonuclease BamHI
  • Deoxyribonuclease HindIII
  • BglII endonuclease
  • Deoxyribonucleases, Type II Site-Specific