Acquired homozygosity of the rearranged bcr allele during the acute
leukemic phase of a patient with Ph-negative chronic myeloid leukemia
AE Reeve, CM Morris and PH Fitzgerald
Department of Biochemistry, University of Otago, Dunedin, New Zealand.
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.
Volume 72,
Issue 1,
pp. 24-28,
07/01/1988
Copyright © 1988 by The American Society of Hematology
