A New Variant Translocation of t(15;17) in a Patient with Acute Promyelocytic Leukemia (M3): t(15;19;17)(q22;p13;q12)

The reciprocal translocation (15;17) is specifically associated with acute promyelocytic leukemia [APL; M3 subtype according to French-American-British (FAB) classification]. A few patients with this disease have complex variant translocations. We describe a patient with M3 carrying t(15;19; 17)(q22;p13;q12), which is a new type of variant translocation. The karyotypic interpretation was confirmed by Southern blot analysis with the use of RARα and by fluorescence in situ hybridization (FISH) with the use of painting probes of chromosomes 15, 17, and 19 and a (15;17) translocation DNA probe. The results support the idea that the key event in APL is the formation of fusion gene PML/RARα on the der(15).