Unique RUNX1 gene rearrangements in acute myeloid Leukemia (AML)

Case 1: A 9year old male was referred for fever, fatigue, and pancytopenia. Bone marrow analysis revealed hypercellularity with a mixture of myeloblasts and immature monocytes comprising 90% of cells as determined by both morphology and flow cytometry. Molecular analysis for mutations in FLT3, NMP1 and C-KIT were negative, and FISH revealed rearrangement of RUNX1 locus in the chromosome 7p22 region. analysis confirmed this finding, revealing a unique translocation:46,XY, t(7;21) (p22;q22). Three adults and one child have been reported in the literature with AML or high grade MDS with t(7;21) involving RUNX1-ubiquitin-specific protease gene (USP42) fusion; however, no consistent prognostic information has emerged from these cases to date.1 Our patient had reinduction chemotherapy and is currently in remission, awaiting stem cell transplant.