title: Patterns and frequencies of acquired and constitutional uniparental isodisomies in pediatric and adult B-cell precursor acute lymphoblastic leukemia.
abstract: Single nucleotide polymorphism (SNP) arrays are increasingly being used in clinical routine for genetic analysis of pediatric B-cell precursor acute lymphoblastic leukemias (BCP ALL). Because constitutional DNA is not readily available as a control at the time of diagnosis, it is important to be able to distinguish between acquired and constitutional aberrations in a diagnostic setting. In the present study we focused on uniparental isodisomies (UPIDs). SNP array analyses of 143 pediatric and 38 adult B-cell precursor acute lymphoblastic leukemias and matched remission samples revealed acquired whole chromosome or segmental UPIDs (wUPIDs, sUPIDs) in 32 cases (18%), without any age- or gender-related frequency differences. Acquired sUPIDs were larger than the constitutional ones (mean 35.3 Mb vs. 10.7 Mb; P < 0.0001) and were more often terminally located in the chromosomes (69% vs. 4.5%; P < 0.0001). Chromosomes 3, 5, and 9 were most often involved in acquired wUPIDs, whilst recurrent acquired sUPIDs targeted 6p, 9p, 9q, and 14q. The majority (56%) of sUPID9p was associated with homozygous CDKN2A deletions. In pediatric ALL, all wUPIDs were found in high hyperdiploid (51-67 chromosomes) cases and an extended analysis, also including unmatched diagnostic samples, revealed a higher frequency of wUPID-positivity in higher modal number (56-67 chromosomes) than in lower modal number (51-55 chromosomes) high hyperdiploid cases (34% vs. 11%; P = 0.04), suggesting different underlying mechanisms of formation of these subtypes of high hyperdiploidy. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Genetics, Lund University, Lund, Sweden.
authors.forename: Kristina B
authors.initials: KB
authors.lastname: Lundin
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Genetics, Lund University, Lund, Sweden.|Department of Clinical Genetics, Office for Medical Services, Division of Laboratory Medicine, Lund, Sweden.
authors.forename: Linda
authors.initials: L
authors.lastname: Olsson
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Genetics, Lund University, Lund, Sweden.
authors.forename: Setareh
authors.initials: S
authors.lastname: Safavi
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Genetics, Lund University, Lund, Sweden.
authors.forename: Andrea
authors.initials: A
authors.lastname: Biloglav
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Genetics, Lund University, Lund, Sweden.
authors.forename: Kajsa
authors.initials: K
authors.lastname: Paulsson
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Genetics, Lund University, Lund, Sweden.|Department of Clinical Genetics, Office for Medical Services, Division of Laboratory Medicine, Lund, Sweden.
authors.forename: Bertil
authors.initials: B
authors.lastname: Johansson
mesh_terms: D000328:Adult; D002648:Child; D006801:Humans; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*