Objective: To detect the expression of the fusion genes resulting from chromosome abnormalities in childhood acute lymphoblastic leukemia(ALL) and its conformity to WHO classification.
Methods: Sixty-two children with ALL were investigated. The expression of fusion genes was determined by multiplex reverse transcription-polymerase chain reaction (RT-PCR), karyotyping (R band) and immunophenotyping (by flow cytometry) were also performed.
Results: Of the 62 patients, 23(37.1%) were found to carry 13 different fusion genes. The patients with immunophenotype of Pre-B-ALL were found to carry: TEL/AML1(3 cases); E2A/PBX1, E2A/HLF, TLS/ERG, MLL/AF4, MLL/AF9, MLL/AF10, MLL/AFX-MLL/AF6-MLL/ELL, MLL/AF6-MLL/ELL, dupMLL (one case for each); and HOX11 (6 cases). The patients with immunophenotype of Pre-T-ALL were found to carry: TAL1D (4 cases, one is also found to have HOX11 expression); and HOX11 (2 cases). The multiplex RT-PCR in combination with chromosome analysis revealed genetic abnormalities in 69.4%(43/62) of childhood ALL.
Conclusion: Multiplex RT-PCR combined with chromosome analysis and immunophenotyping can provide reliable and helpful information for the diagnosis, therapy evaluation and prognosis prediction in childhood ALL, which may also serve as a basis on which to implement the criteria of WHO classification.