The Clinical Application Of Fluorescence In Situ Hybridization&Chromosome Banding Technology In The Diagnosis Of Childhood Hematologic Malignancy

Objective To compare fluorescence in situ hybridization (FISH) with chromosomebanding technology on clinical application in the diagnosis of pediatric hematologic malignancy.Method Chromosomal abnormalities from two hundred and twenty eight patientswith hematologic malignancy were retrospectively analyzed by Double-FISH (D-FISH)and chromosome R-banding technology in Children’s Hospital of Soochow Universityfrom November2011to December2013.Results1.Chromosome R-banding technology: One hundred and ninty-eightchildren,s samples were analyzed successfully,thirty specimen had no split phase, whichmeant ineffective analysis(the reasons were few cells,numbers of specimens,cells failureto be cultured or banded,and poor quality of chromosomes).Among cases,one hundred andthirty-two patients with acute lymphoblastic leukemia(ALL) were evaluated,includingnormal karyotypes in fifty-nine cases,ten kinds of independent number abnormality(twentycases) and thirteen kinds of independent structural abnormality(fifteen cases),both numbersand structural abnormality in ten cases.And twenty-eight cases,can not be analysedsuccessfully.Fifty-eight cases with acute myeloid leukemia children(AML) were analysed[excluding acute promyelocytic leukemia(APL)].They included normal karyotype inforteen children,eight kinds of numbers abnormality(six cases),thirteen kinds of structuralabnormality(twenty-four cases),both number and structural abnormality in twelvecases,accompanied with twenty-eight cases unsuccessfully.APL cases,results includedtwo kinds of number abnormality(two cases:+15,+19) and one kind of structuralabnormality[sixteen cases: t(15;17)(q22;q21)].Among thirteen children withmyelodysplastic syndrome(MDS), they included ten cases with normal karyotype,two cases with three kinds of sole number abnormality(containing+8,+X,-7),one case withabnormalities-7,-16,+21,5q-,11p+,12p-.Only two patients with non-Hodgkin,slymphoma(NHL),they showed us one normal karyotype and one hypo-triploid case.Allthree children with chronic myeloid leukemia(CML) owned t(9;22)(q34;q11).Three caseswith juvenile myelomonocytic leukemia(JMML) had two cases with normal karyotype andone with5q-.2.FISH: All two hundren and twenty-eight cases were analysed.Among onehundred and thirty-two patients with ALL, forty-seven cases,results were negative.Therewere three kinds of structural abnormality(twenty-eight cases) which containedTEL/AML1,BCR/ABL and MLL rearrangement.And fifty-one cases had sole numberabnormality.Six cases existed two kinds of abnormalities aboved.FISH array has detectedtwenty-one abnormal cases while twenty-eight cases with karyotype bandingunsuccessful.However,t(12;21)/TEL-AML1can be only detected by FISH.Except forAPL,twenty-seven cases from fifty-eight patients with AML were normal karyotypes.Therewere four kinds of number abnormality(two cases) which covered+8,-Y,+21,+21*2,andthree kinds of structural abnormality(twenty-eight cases) contain AML1/ETO,CBFβ-MYH11,and MLL rearrangement,including one case with MLL rearrangement casecombined number abnormality with+8.All seventeen children with APL existed fusiongene of PML-RARα.Four kinds of number abnormality(four cases namely+8,+X,-7,+11)and one structural abnormality (case combined-7) were detected in thirteen MDS patientswith MDS.one case with NHL had number abnormality(+10,+12，+17，+21*3) which washypo-triploid karyotype in the banding examination.Another one was normalchromosome.BCR/ABL fusion gene was positive in three CML cases.For two patients withJMML,one owend normal karyotype,and another had–Y.Conclusion Chromosome banding and FISH technology play a vital role in thediagnosis and risk-stratification in pediatric hematologic malignancy. When combinedthese two methods, cytogenetics anomaly can be found well.1) Karyotypes analysis canget the information of unknown chromosome abnormalities, only found in split-phase cells.FISH can only find known abnormalities, not only in split-phase cells, but in inter-phasecells.2) FISH array is superior to chromosome banding when known chromosomalabnormalities are detected, including on positive rate and consuming time. They are indispensable for the risk-stratification in childhood ALL and AML.3) These can furtherconfirm the diagnosis of MDS, or JMML, or CML.4) NHL’s subgroup can be tailored byevaluation of FISH for pathologic biopsy specimens.