Different clones of t(1;12)/t(12;12) involving the ETV6 gene in a case of acute myeloid leukemia

We describe here a case of a 77-year-old Japanese man who developed acute myeloid leukemia (AML-M2). Chromosome analysis of the bone marrow blast cells showed 46,XY,del(7q) at onset, and after relapse, two clones, 46,XY,t(1;12) and 46,XY,del(7q),t(12;12), were present. Fluorescence in situ hybridization analysis confirmed that each clone with the 12p abnormality involved the ETV6 gene. These findings suggest that the ETV6 gene rearrangements in this case were apparently independent of contribution to leukemogenesis, because this cytogenetic aberration appeared as a secondary change. To our knowledge, this is the first report of two different clones with ETV6 gene rearrangements in the same patient.