In hematologic malignancies chromosome aberrations generating fusion genes include cryptic deletions. In a patient with acute myeloid leukemia and normal karyo-type we discovered a new cryptic 9q34 deletion and here report the cytogenetic and molecular findings. The 9q34 deletion extends 2.5 megabases and juxtaposes the 5′ TAF-I to the 3′ CAN producing a TAF-I/CAN fusion gene. TAF-I/CAN transcribes into two fusion proteins bearing either TAF-Iα or TAF-Iβ moieties. We set up molecular assays to monitor the chimeric TAF-Iα/CAN and TAF-Iβ/CAN transcripts which, after hematopoietic stem cell transplantation from an HLA-identical sibling, were no longer detected.
