A case of chronic myelogenous leukemia with e8a2 fusion transcript

The Philadelphia chromosome and its corresponding fusion gene, BCR–ABL, is one of the best-known genetic abnormalities in hematological malignancies. Major BCR–ABL translocation is much more common in chronic myelogenous leukemia (CML) and minor BCR–ABL in acute lymphoblastic leukemia. We experienced an extraordinarily rare case of CML with an e8a2 variant. An unusual band, other than the common transcripts, was observed in reverse transcription–polymerase chain reaction (RT-PCR) for the BCR–ABL gene rearrangement. Sequence analysis of the PCR product revealed an 1172-bp e8a2 fusion with a 14-bp insertion of ABL intron Ia. The patient achieved a complete hematological response 3 months after imatinib treatment. It is necessary to keep in mind that an unexpected band revealed with RT-PCR may mean the presence of unusual fusion gene.