ABL-BCR mRNAs transcribed from chromosome 9q+ in Philadelphia-chromosome-positive chronic myeloid leukaemia.

Polymerase chain reaction amplification of reverse transcription products has demonstrated the presence of abl-bcr hybrid mRNAs in RNA from peripheral blood leucocytes of Philadelphia-chromosome-positive chronic myeloid leukaemia patients; such hybrid mRNAs can contain either of the alternative first exons of c-abl. A survey of 12 CMLs has shown that abl-bcr mRNAs occur in the leucocytes of some, but not all, patients, and that they are present both in chronic-phase and acute-phase leucocytes.