THE TYPE OF BCR ABL JUNCTION DOES NOT PREDICT THE SURVIVAL OF PATIENTS WITH PH1-POSITIVE CHRONIC MYELOID-LEUKEMIA/

The prognostic value of the location of the breakpoint on chromosome 2 2 in patients with Ph1+ chronic myeloid leukaemia (CML) is still cont roversial. We analysed both DNA rearrangement and transcript type in a new continuous series of CML patients. By Southern blotting analysis, we found that, out of 72 patients, 43 had a 5' rearrangement and 29 a 3' one, of the 43 5'-rearranged patients, 35 carried an a2b2 transcri pt and eight an a2b3 one, while, of the 2 9 patients rearranged in the 3' part of the M-BCR area, 26 had an a2b3 transcript, one had an a2b2 transcript and two carried both types of transcript. Thus, mRNA studi es allow to detect an a2b3 transcript in 17.7% of 5' rearranged patien ts. However, no correlation was observed between type of transcript an d survival, as after DNA studies.