T(1-5)(Q23-Q33) IN A PATIENT WITH HIGH-RISK B-LINEAGE ACUTE LYMPHOBLASTIC-LEUKEMIA

The t(1;5)(q23;q33) is a rare genetic anomaly that was reported previo usly in two infants with a myeloproliferative disorder and eosinophili a and in one adult patient with acute nonlymphocytic leukemia (ANLL). A 13-year-old boy with high-risk early pre-B acute lymphoblastic leuke mia (ALL) who presented to our institution carried the t(1;5)(q23;q33) . He had an initial blast count of 230 x 10(9)/L and responded poorly to prednisone. Complete remission ICR) was achieved, and he had a bone marrow (BM) relapse 3 months after despite intensive consolidation th erapy He underwent allogeneic BM transplantation (BMT) from a human le ukocyte antigen (HLA)-identical sibling in early relapse with total bo dy irradiation (TBI) and cyclophosphamide conditioning. He had a short second CR with a central nervous system (CNS) relapse on day +106 aft er BMT. Two of the previously reported patients also did not respond t o chemotherapy. The t(1;5)(q23;q33) appears to be a rare lineage nonsp ecific anomaly related to hematologic malignancies that are resistant to current therapy.