A Novel Translocation Involving RUNX1 and HOXA Gene Clusters in a Case of Acute Myeloid Leukemia with t(7;21)(p15;q22).

Translocations involving chromosome 21q22 are frequently observed in hematologic malignancies including acute myeloid leukemia (AML), most of which have been known to be involved in malignant transformation through transcriptional dysregulation of Runt-related transcription factor 1 (RUNX1) target genes. Nineteen RUNX1 translocational partner genes, at least, have been identified, but not Homeobox A (HOXA) genes so far. We report a novel translocation of RUNX1 into the HOXA gene cluster in a 57-year-old female AML patient who had been diagnosed with myelofibrosis 39 months ahead. G-banding showed 46,XX,t(7;21)(p15;q22). The involvement of RUNX1 and HOXA genes was confirmed by fluorescence in situ hybridization.