title: Hyperdiploidy and E2A-PBX1 fusion in an adult with t(1;19)+ acute lymphoblastic leukemia: case report and review of the literature.
abstract: The t(1;19)(q23;p13), detected cytogenetically in 5-6% of cases, is one of the most common translocations in childhood acute lymphoblastic leukemia (ALL). Most t(1;19)+ ALLs are pseudodiploid or contain fewer than 50 chromosomes, are classified as pre-B based on expression of cytoplasmic, but not surface, immunoglobulin (clg+/slg-), express a characteristic pattern of cell surface antigens, and contain E2A-PBX1 fusion mRNAs. A minority of cases are early pre-B (clg-/slg-), do not express the characteristic pattern of cell surface antigens, and lack E2A-PBX1 fusion mRNAs. These latter cases are frequently hyperdiploid, with a modal chromosome number of 55-57. The incidence of the t(1;19) in adults with ALL (approximately 3%) appears to be similar to that observed in children, but the genetic and immunophenotypic features of adult t(1;19)+ ALL have not been described extensively. We report a case of t(1;19)+ ALL occurring in a 38-year-old man in the setting of hyperdiploidy > 50. Despite this feature, this case was pre-B, conformed to the classic t(1;19) immunophenotype, and expressed E2A-PBX1 fusion mRNAs. This prompted us to review the published literature on ploidy and genetic features of t(1;19)+ ALLs. Overall, E2A-PBX1 fusion occurred in 95% (102/107) of t(1;19)+ B-lineage ALLs with 50 or fewer chromosomes, 80% of which were pseudodiploid, vs. only 25% (2/8) of t(1;19)+ ALLs with more than 50 chromosomes.
authors.affiliation: Department of Pediatrics, University of Colorado School of Medicine, Denver, USA. Stephen.Hunger@UCHSC.edu
authors.forename: S P
authors.initials: SP
authors.lastname: Hunger
authors.forename: T
authors.initials: T
authors.lastname: Sun
authors.forename: A F
authors.initials: AF
authors.lastname: Boswell
authors.forename: A J
authors.initials: AJ
authors.lastname: Carroll
authors.forename: L
authors.initials: L
authors.lastname: McGavran
mesh_terms: D000328:Adult; D002871:Chromosome Banding; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D016130:Immunophenotyping; D007621:Karyotyping; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D011003:Ploidies; D016133:Polymerase Chain Reaction; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis; D014178:Translocation, Genetic / Q000235:genetics
chemical_list: D018398:Homeodomain Proteins; D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C089847:E2A-Pbx1 fusion protein