TRANSLOCATION OF BCR TO CHROMOSOME-9 IN A PHILADELPHIA-NEGATIVE CHRONIC MYELOID-LEUKEMIA

We report the case of a patient having Philadelphia-negative, bcr-abl- positive chronic myeloid leukemia. In situ hybridization showed the pr esence of the bcr-abl fusion on the chromosome 9 long arm in all mitos es observed. Stability of the disease was very difficult to obtain bec ause of serious adverse effects to interferon and chemotherapy, mainly grade IV neutropenia, and a blast crisis occurred 12 months after dia gnosis. Only three other patients with such presentation (Philadelphia negative, bcr-abl positive with bcr-abl fusion on the chromosome 9 lo ng arm) have been reported, with a poor therapeutic response and outco me in two of them. Translocation of BCR to chromosome 9 may therefore have a worse prognosis than translocation of ABL to chromosome 22 in P hiladelphia-negative chronic myeloid leukemia.