The Clinical Study On Screening For Common Fusion Genes Of Pediatric Leukemia

Objective: To investigate the prognosis of pediatric leukemia related to chromosomestructural abnormalities which involving29common fusion genes. To assess the valueof common fusion genes analysis in the diagnosis and classification of childhoodleukemia.Methods: Multiplex nested reverse transcription polymerase chain reaction(RT-PCR)was performed on143newly diagnosed patients of pediatric leukemia to detect29common fusion genes,and positive patients were monitored with the level of fusiongene by RT-PCR.To explore the relationship between fusion gene and the prognosis ofpediatric leukemia.Results: Eight fusion genes were detected in143cases of pediatric leukemia,including TEL/AML1,AML1/ETO,PML/RARα,BCR/ABL(p190,p210),MLL/AF9,E2A/PBX1,Hox11,TLS/ERG.Twelve children were positive for TEI/AML1,early treatment response were good.There are8cases still in CR.Three of them already stopped the treatment depending on the protocol.One case relapsed after the treatment was completed.Eight children were positive for AML1/ETO,they were reachedCR after the initial induction chemotherapy.There are4cases still in CR.Two ofthem already stopped the treatment.One case has been died according to gave uptreatment after2courses of chemotherapy.One case relapsed after the treatmentwas completed.Seven cases namely PML/RARα,they were reached CR after theinitial induction chemotherapy.Five examples now as before in CR,two of them already stopped the treatment depending on the protocol.Four cases namely BCR/AB L(p190）,early treatment response were poor,one case gave up therapy,other3cases had arrived CR after latter strengthened chemotherapy.Two patients have received bone marrow transplantation（One case relapsed after transplantation,the other case had arrived CR2months after transplantation).One patient has received strengthened chemotherapy,still got relapsed after CR6months.Five cases namelyBCR/ABL(p210）,2cases of ALL has been died according to gave up treatment,One case of ALL relapsed after transplantation.Two cases of CML accepted chemotherapy with Gleevec,now as before in CR.Two cases namely MLL/AF9,one case of ALL got good early treatment response,one case of AML reached CR after the initial induction chemotherapy,they already stopped the treatment dependingon the protocol.Three children were positive for E2A/PBX1.One of them got poorresponse in early treatment,other two cases was opposite.At present,they are stillin CR.Four children were positive for HOX11,one case of ALL has been diedaccording to gave up treatment，other two were good in early treatment response,now as before in CR.One case of AML reached CR after the initial induction chemotherapy,now as before in CR.One case namely TLS/ERG,early treatment response was poor.It is already stopped the treatment depending on the protocol.Conclusion: Detection of common fusion genes could screen29types of chromosomestructural aberrations at the same time.And it would refine the karyotypeanalysis.Screening of common fusion genes is an important tool which could provideuseful and reliable molecular genetic information for the diagnosis and treatment ofleukemia,which may also serve as a basis on individualized treatment.Fusion genes asdetection indicators for MRD plays an irreplaceable role in the treatment of pediatricleukemia.