Identification of TEL-AML1 and E2A/PBX1 fusion gene in childhood acute lymphoblastic leukemia

Objective To discuss the role of fluorescence in situ hybridization(FISH) in t(12;21) and t(1;19) detection in pediatric cases with acute lymphoblastic leukemia.Methods t(12;21)/TEL-AML1 fusion gene and t(1;19)/E2A/PBX1 was identified in bone marrow mononuclear cells from 63 newly diagnosed childhood ALL patients by FISH and conventional cytogenetic analysis(CCA).Results 16 cases were found with a t(12;21) by FISH.3cases were found with a t(1;19) by FISH.The incidence of the t(12;21) was 25.4% and the t(1;19) was 4.8% in newly diagnosed pediatric ALLs.Conclusion t(12;21)/TEL-AML1 and t(1;19)/E2A/PBX1 fusion gene is common cytogenetic translocations in Chinese pediatric ALLs,but it always cannot be identified by routine CCA.Other molecular methods,e.g.FISH are powerful in detecting such a cryptic genetic translocation.