title: Interphase FISH to detect PBX1/E2A fusion resulting from the der(19)t(1;19)(q23;p13.3) or t(1;19)(q23;p13.3) in paediatric patients with acute lymphoblastic leukaemia.
abstract: Approximately 6% of paediatric patients with precursor B-cell acute lymphoblastic leukaemia (B-ALL) harbour a rearrangement involving the gene regions of PBX1 (1q23) and E2A (19p13.3) which is visualized cytogenetically either as a der(19)t(1;19)(q23;p13.3) or the less common balanced t(1;19)(q23;p13.3). Unfortunately, no commercial dual-colour, double fusion fluorescence in situ hybridization (D-FISH) strategies are available to detect this recurrent anomaly. Therefore, we have created a D-FISH assay to detect these translocations and monitor minimal residual disease. This probe set was created using four bacterial artificial chromosomes (BACs) corresponding to the PBX1 gene region at 1q23 and four BACs corresponding to the E2A gene region at 19p13.3. We analysed 30 negative bone marrow controls and 20 diagnostic and post-treatment specimens from 13 paediatric B-ALL patients with a cytogenetically defined 1;19 translocation. Once unblinded, the results demonstrated that our D-FISH method effectively identified all diagnostic samples as abnormal and identified disease in four post-treatment samples that were previously considered to be normal by conventional cytogenetic analysis. The development of this FISH strategy for the detection of der(19)t(1;19)(q23;p13.3) and t(1;19)(q23;p13.3) proved to be an effective technique, allowing both the detection of disease in diagnostic samples and in post-treatment samples.
authors.affiliation: Department of Laboratory Medicine and Pathology, Division of Laboratory Genetics, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Brandon M
authors.initials: BM
authors.lastname: Shearer
authors.forename: Heather C
authors.initials: HC
authors.lastname: Flynn
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Knudson
authors.forename: Rhett P
authors.initials: RP
authors.lastname: Ketterling
mesh_terms: D000293:Adolescent; D002051:Burkitt Lymphoma / Q000175:diagnosis / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D007621:Karyotyping; D009363:Neoplasm Proteins / Q000235:genetics; D018365:Neoplasm, Residual; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D011379:Prognosis; D012189:Retrospective Studies; D014178:Translocation, Genetic
chemical_list: D018398:Homeodomain Proteins; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; C089847:E2A-Pbx1 fusion protein