A new complex translocation t(5;17;15)(q11;q21;q22) in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is associated with the t(15;17)(q22;q21) translocation which causes the fusion of the retinoic acid alpha gene (RARA) on 17q21 to the promyelocytic leukemia gene (PML) on 15q22. The two chimeric genes, PML/RARA and RARA/PML, are thought to play a role in leukemogenesis. A small proportion of patients with APL have complex or simple variants of this translocation. We report the case of a 22-year-old woman with APL carrying a complex variant translocation t(5;17;15)(q11;q12;q22) confirmed by G-banding, reverse transcription polymerase chain reaction (RT-PCR), fluorescence in situ hybridization(FISH), and spectral karyotyping analysis (SKY). The patient achieved complete remission with all-trans retinoic acid treatment and chemotherapy. These results illustrate the usefulness of combined analysis consisting of G-banding, RT-PCR, FISH, and SKY methods to identify the PML/RARA fusion gene in cases with variant t(15;17).