Detection of PML/RARα Fusion Gene in Acute Promyelocyte Leukemia

Objective To investigate the value of fluorescence in situ hybridization(FISH) technique in the detection of fusion gene in acute promyelocyte leukemia(APL).Methods FISH was used to detect the PML/RARα fusion gene in 30 patients with newly diagnosed and 20 cases undetermined as acute promyelocyte leukemia(APL).FISH was also utilized to trace the PML-RARα fusion gene changes in patients during the courses of treatment.Results Among 30 cases,27 were PML/RARα positive.1 case was detected AML1/ETO fusion gene.In 20 unconfirmed APL or AML-M2,3 cases showed AML1/ETO and 10 showed PML/RARα fusion gene.6 patients with negative fusion gene after 12 month of CR.The results of the 2 years'follow-up after CR showed that there were 7 patients with higher proportion of PML/RARa fusion gene.These 7 patients relapsed within 3 months.Conclusion FISH is more sensitive for molecularly diagnosis of APL,and can identify the precise location of the fusion signals in complex karyotype.It can be used to diagnose,guide the suitable chemotherapy regimen and supervise the efficacy of the treatment in patients with APL.