Identification of TEL-AML1 fusion gene in childhood acute lymphoblastic leukemia

Abstract

Objective To detect expression of TEL-AML1 fusion genes in pediatric cases with acute lymphoblastic leukemia(ALL) and discuss the role of reverse transcriptase polymerase chain reaction(RT-PCR)and fluorescence in situ hybridization(FISH) in detection of t(12 ;21) and the clinical significance. Methods TEL-AML1 fusion gene was identified in bone marrow munonuclear cells from 31 newly diagnosed childhood ALL patients by NRT-PCR, FISH and conventional cytogenetic analysis (CCA). Results TEL-AML1 fusion gene was found in 7 out of 31 cases, accounting for 22.6 % in pediatric ALL, and 7 out of 31 cases accounting for 25.9 % in B-ALL Seven cases were found with t (12;21) by FISH and NRT-PCR. The incidence of the t(12;21) was 22.6 % in newly diagnosed pediatric ALLs. Conclusion It is concluded that TEL-AML1 rearrangement is a frequent molecular abnormality in childhood ALL. t(12;21) is the most common cytogenetic translocations in Chinese pediatric ALLs, but it is always difficult to identify by routine CCA.Other molecular methods, e.g. NRT-PCR and FISH are powerful in detecting such a critical genetic translocation. Key words: Leukemia; lymphoblastic; acute; TEL-AML1 fusion gene; Polymerase chain reaction; In situ hybridization; fluorescence