title: The TEL-AML1 fusion accompanied by loss of the untranslocated TEL allele in B-precursor acute lymphoblastic leukaemia of childhood.
abstract: The TEL-AML1 fusion which results from the t(12;21) rearrangement in childhood B-precursor acute lymphoblastic leukaemia (B-precursor ALL) is often accompanied by loss of the untranslocated TEL allele. From 32/109 children with B-precursor ALL screened for these abnormalities, we found evidence for del 12p, including the loss of the untranslocated TEL allele, to be the secondary event to take place in the leukaemic cells from those patients positive for these abnormalities. This suggests that the initial or predisposing event is the generation of a TEL-AML1 fusion, followed by the promoting event of a deletion of a gene(s) on 12p. A striking characteristic of the leukaemic cells in 61% of the patients showing t(12:21). was the substantial evolution of the primary clonal line containing the reciprocal TEL-AML1 fusion. We were able to show loss of normal TEL in the same patients by interphase fluorescence in situ hybridisation (FISH) analysis and reverse-transcriptase polymerase chain reaction (RT-PCR).
authors: Molecular Haematology Unit, Institute of Child Health, Great Ormond Street Hospital for Sick Children, London, UK. H.Kempski@ich.ucl.ac.uk
authors: H M
authors: HM
authors: Kempski
authors: N T
authors: NT
authors: Sturt
mesh_terms: D000483:Alleles; D002648:Child; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins / Q000235:genetics; D017353:Gene Deletion; D006801:Humans; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000209:etiology / Q000235:genetics*; D050783:Proto-Oncogene Proteins c-ets; D012097:Repressor Proteins / Q000235:genetics; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; D015514:Oncogene Proteins, Fusion; D050783:Proto-Oncogene Proteins c-ets; D012097:Repressor Proteins; D000097764:ETS Translocation Variant 6 Protein; C102421:TEL-AML1 fusion protein