Value of fluorescence in situ hybridization in Identification of fusion gene in pediatric cases with acute lymphoblastic leukemia

Objective:To discuss the role of interphase fluorescence in situ hybridization(I-FISH) in TEL AML1 and BCR/ABL fusion gene detection in pediatric cases with acute lymphoblastic leukemia.Methods: Dual color I-FISH and conventional cytogenetic analysis(CCA) were combined to detect t(12;21) TEL/AML1 and t(9;22) BCR/ABL fusion gene in bone marrow mononuclear cells from 35 newly and 4 oddly pediatric ALL patients.Results: Twelve cases were found the TEL/AML1 fusion gene by FISH(30.8%).But no dubious t(12;21) gene was detected by CCA.Four cases were found the BCR/ABL fusion gene by FISH(10.3%).Only 1 case was found dubious t(9;22) gene by CCA,the incidence was 2.5%.TEL/AML1 fusion gene was more than BCR/ABL fusion gene in pediatric ALL patients and showed lower peripheral tumor load in diagnosis.Conclusion: Dual color IFISH is more sensitive and specific than conventional cytogenetic analysis(CCA)in the identification of TELAML1 and BCR/ABL fusion gene.So it is playing a significant role in diagnosis and therapy of pediatric cases with acute lymphoblastic leukemia.