Two Novel Translocations That Disrupt the RUNX1 Gene in Acute Myeloid Leukemia.

Translocations involving 21q22 are commonly observed in both de novo and therapy-related acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). They often result in the disruption of RUNX1 and give rise to fusion genes consisting RUNX1 and different partner genes which contribute to leukemogenesis. At present, at least 21 such translocations have been reported in the literature. We report here two novel translocations involving the RUNX1 gene: t(1;21)(q12;q22) in a 53-year-old female with AML-M5b and t(11;21)(q13;q22) in a 65-year-old male with AML-M2. The abnormalities revealed by R-banding karyotypic analysis were confirmed by interphase and metaphase fluorescence in situ hybridization (FISH), chromosome painting (CP), and M-FISH.