e6a2 BCR/ABL1 fusion with cryptic der(9)t(9;22) deletions in a patient with chronic myeloid leukemia.

This is the first report of e6a2 and e1a2 BCR/ABL1 positive chronic myeloid leukemia (CML) with cryptic deletions of the 5'ABL1 and 3'BCR in separate clones which differ in genomic regions of the deleted der(9). Both deletions were detected throughout monitoring. Imatinib mesylate stabilized this CML with rare genetic aberrations for a relatively long time.