RESUMO
To investigate the biological characteristics of the variant translocation der ins (17;15) in a patient with acute promyelocytic leukemia (APL), the conventional G-banding technique, interphase fluorescence in situ hybridization (int-FISH), RT-PCR, gene scanning, gene sequence and flow cytometry were performed. The results indicated that the variant translocation der ins (17, 15) observed by G banding technique was a rare type, the int-FISH assay by using dual-color pml/raralpha fusion probes confirmed the cytogenetic findings. The detection results of other molecular methods demonstrated the existence of the whole pml/raralpha fusion gene, while this case had insertion variant translocation. This patient got complete remission by using combined chemotherapy, and survives with continuous complete remission during following up for 1 year. In conclusion, the variant translocation der ins (17; 15) is rare type in APL, its incidence is lower, several signal types in detection of int-FISH were observed and the combination chemotherapy for this patient showed more obvious efficacy.