Molecular analysis of the t(1;19)(q23;p13) translocation observed in adult leukemias.

We report three cases of adult leukemias with the t(1;19)(q23;p13) translocation, two with acute lymphoblastic leukemia (ALL:L2) and one with megakaryoblastic crisis of chronic myelocytic leukemia. Only one patient with ALL showed the same E2A/PBX1 fusion transcripts as those observed in childhood ALLs with the t(1;19) by RNA-based polymerase chain reaction. This patient survived for 8 months only from the time of his diagnosis. On the other hand, the other two cases were negative for the E2A/PBX1 fusion and one of them with ALL remains in remission. Our observations suggest that there could be heterogeneity in the molecular events among adult leukemias carrying the t(1;19) and that the E2A/PBX1 fusion formation might also be associated with an adverse treatment outcome in adult leukemias as in childhood leukemias.