[Detection of bcr/abl fusion gene by dual color-dual fusion fluorescence in situ hybridization].

This study was aimed to investigate the sensitivity and clinical application of interphase-dual-color and dual-fusion fluorescence in situ hybridization (DC-DF-FISH). The bcr/abl fusion gene was detected by FISH with dual-color and dual-fusion bcr/abl DNA probe in interphase cells of bone marrow from 1295 specimens. Retrospective analysis for the cases was performed by the means of conventional cytogenetic analysis (CCA) and FISH. The results indicated that in 1295 specimens from 539 patients, 456 specimens were positive involved in 310 patients, the karyotypes of 18 patients were normal, 5 patients failed to karyotyping analysis. About 75.5% (234/310) of positive patients displayed the typical DC-DF-FISH signal pattern, 76 patients showed atypical DC-DF-FISH signal patterns, 66 cases out of which showed variant signal, 16 patients displayed typical variant signals (1Y2G2R), 50 patients displayed deletion ABL and/or BCR signal. In 213 patients, the negative rate was 60% (128/213) after the treatment, 12 patients were sometimes negative and sometimes positive during the process of the treatment. It is concluded that DC-DF-FISH can be used to detect karyotypes with masked or variant Ph, gene deletion and minor residual disease (MRD) in process of treatment. The dual-color FISH technique is a much more sensitive and accurate tool for monitoring MRD and monitoring relapse, which is a necessary supplement to CCA.