title: Molecular Analysis of Pediatric Oligodendrogliomas Highlights Genetic Differences with Adult Counterparts and Other Pediatric Gliomas.
abstract: Oligodendroglioma represents a distinctive neoplasm in adults but similar neoplasms occur rarely in children. We studied 20 cases of pediatric oligodendroglioma by SNP array (median age 9 years, range 1-19; 15 grade II and 5 grade III). Cytogenetic abnormalities were present in 8 (53%) grade II and all five anaplastic oligodendrogliomas. Most changes were in the form of deletion and copy neutral loss of heterozygosity (LOH). The most common abnormality was 1p deletion (n = 5). Whole arm 1p19q co-deletion was present in three cases from adolescent patients and 9p loss in 3, including one low-grade oligodendroglioma with CDKN2A homozygous deletion. Common losses were largely limited to the anaplastic subset (n = 5) and included 3q29 (n = 3), 11p (n = 3), 17q (n = 3), 4q (n = 2), 6p (n = 2), 13q (n = 2), 14q (n = 2), 17p (n = 2) and whole Ch 18 loss (n = 2). Gains were non-recurrent except for whole Ch 7 (n = 2) and gain on 12q (n = 2) including the MDM2 locus. Possible germ line LOH (or uniparental disomy) was present in seven cases (35%), with one focal abnormality (22q13.1-13.2) in two. BRAF-KIAA1549 fusions and BRAF p.V600E mutations were absent (n = 13 and 8). In summary, cytogenetic alterations in pediatric oligodendrogliomas are characterized mostly by genomic losses, particularly in anaplastic tumors.
authors.affiliation: Department of Pathology, Division of Neuropathology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: David
authors.initials: D
authors.lastname: Nauen
authors.affiliation: Department of Pathology, Division of Neuropathology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Lisa
authors.initials: L
authors.lastname: Haley
authors.affiliation: Department of Pathology, Division of Neuropathology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Ming-Tseh
authors.initials: MT
authors.lastname: Lin
authors.affiliation: Department of Pathology, Division of Neuropathology, University of California San Francisco School of Medicine, San Francisco, CA.
authors.forename: Arie
authors.initials: A
authors.lastname: Perry
authors.affiliation: Laboratory of Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN.
authors.forename: Caterina
authors.initials: C
authors.lastname: Giannini
authors.affiliation: Department of Pathology, Division of Neuropathology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Burger
authors.affiliation: Department of Pathology, Division of Neuropathology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Fausto J
authors.initials: FJ
authors.lastname: Rodriguez
mesh_terms: D000293:Adolescent; D001921:Brain / Q000378:metabolism / Q000473:pathology; D001932:Brain Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D019656:Loss of Heterozygosity; D008297:Male; D060787:Neoplasm Grading; D009837:Oligodendroglioma / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D020641:Polymorphism, Single Nucleotide; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D055815:Young Adult
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf
keywords: BRAF; FISH; SNP array; cytogenetics; oligodendroglioma; pediatric glioma