bcr Rearrangement without juxtaposition of c-abl in chronic myelocytic leukemia

Southern blot analysis detected a bcr gene rearrangement within leukemic cells of a Philadelphia chromosome-negative chronic myelocytic leukemia (CML) patient that led to transcription of a novel 7.3 kb bcr RNA species. Participation of the c-abl oncogene in this genomic recombination could be ruled out by in situ hybridization studies and Northern blot analysis.