title: Philadelphia-positive chronic myelogenous leukemia with breakpoint 5' of the breakpoint cluster region but within the bcr gene.
abstract: We report on the first Philadelphia chromosome (Ph) positive chronic myelogenous leukemia (CML) characterized by a rearrangement within the 5' part of the bcr gene on chromosome 22, but outside the restricted breakpoint cluster region. In situ hybridization studies revealed a translocation of the c-abl oncogene to the Ph chromosome and Northern blot analysis identified a chimeric 8 kb bcr/abl RNA transcript in leukemic cells. These data suggest that 1. less bcr coding sequences than previously assumed may be essential for the putative transforming activity of the rearranged bcr/abl gene and 2. the bcr probes currently used for diagnostic purposes could miss Ph-positive CML cases.
mesh_terms: D000328:Adult; D006801:Humans; D007951:Leukemia, Myeloid / Q000235:genetics*; D008297:Male; D009857:Oncogenes; D010677:Philadelphia Chromosome