Acquired homozygosity of the rearranged bcr allele during the acute leukemic phase of a patient with Ph-negative chronic myeloid leukemia.
A 45-year-old male patient with Ph-negative chronic myeloid leukemia (CML) had rearranged bcr-3' and bcr-5' gene regions in Southern blot studies when leukemia was diagnosed. During development of terminal blast crisis, successive blood samples showed a progressive decrease in the amount of germline bcr DNA and its complete loss by full blast crisis. There were also increased amounts of rearranged bcr DNA consistent with acquired homozygosity. A similar result was obtained with an IgV lambda probe and indicated homozygosity of a significant part of chromosome 22. The bcr-abl gene complex behaves as a somatic dominant in CML, and we suggest that its acquired homozygosity is a mechanism of bcr-abl amplification similar to duplication of the Ph chromosome commonly found in the blast crisis of CML.
Reeve
A E
AE
Department of Biochemistry, University of Otago, Dunedin, New Zealand.
Morris
C M
CM
Fitzgerald
P H
PH
D000483:Alleles; D001752:Blast Crisis / Q000097:blood / Q000235:genetics*; D004247:DNA / Q000097:blood; D006720:Homozygote; D006801:Humans; D007621:Karyotyping; D007951:Leukemia, Myeloid / Q000097:blood / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009693:Nucleic Acid Hybridization; D010677:Philadelphia Chromosome; D011519:Proto-Oncogenes; D014178:Translocation, Genetic
D004247:DNA