title: Comparative genomic hybridization detects specific cytogenetic abnormalities in pediatric ependymomas and choroid plexus papillomas.
abstract: Pathogenesis and genetic abnormalities of ependymomas are not well known and differential diagnosis with choroid plexus tumors may be difficult when these tumors are located in the ventricles. We analyzed 16 samples of primary pediatric ependymomas and seven choroid plexus tumors for significant gains or losses of genomic DNA, using comparative genomic hybridization (CGH). Four ependymoma samples were obtained after surgery for relapse, including one patient whose tumor was analyzed at diagnosis and at first and second relapses. Three out of 16 ependymomas and none of the choroid plexus tumors appeared normal by CGH. In the remaining ependymomas, the number of regions with genomic imbalance was limited. The most frequent copy number abnormality in ependymomas was 22q loss. In one patient from whom multiple samples could be analyzed during tumor progression, no abnormality was present at diagnosis; gain of chromosome 9 and loss of 6q were observed at first relapse and, at second relapse, additional genomic imbalances were loss of 3p, 10q, and chromosome 15. In choroid plexus tumors, recurrent abnormalities were gains of chromosome 7 and region 12q. The recurrent chromosomal abnormalities were clearly different between ependymomas and choroid plexus papillomas (CPP). Recurrent loss of 22q suggests that this region harbors tumor suppressor genes important in the pathogenesis of ependymomas; however, other pathogenic pathways may exist involving 6q and chromosome 10 losses or gain of 1q and chromosome 9. CPP can be distinguished from ependymoma on the basis of CGH abnormalities.
authors.affiliation: Department of Pediatric Oncology, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Grill
authors.forename: Hervé
authors.initials: H
authors.lastname: Avet-Loiseau
authors.forename: Arielle
authors.initials: A
authors.lastname: Lellouch-Tubiana
authors.forename: Nicolas
authors.initials: N
authors.lastname: Sévenet
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Terrier-Lacombe
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Vénuat
authors.forename: François
authors.initials: F
authors.lastname: Doz
authors.forename: Christian
authors.initials: C
authors.lastname: Sainte-Rose
authors.forename: Chantal
authors.initials: C
authors.lastname: Kalifa
authors.forename: Gilles
authors.initials: G
authors.lastname: Vassal
mesh_terms: D001932:Brain Neoplasms / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D016545:Choroid Plexus Neoplasms / Q000235:genetics*; D002869:Chromosome Aberrations; D002872:Chromosome Deletion; D002892:Chromosomes, Human, Pair 22; D004806:Ependymoma / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D009693:Nucleic Acid Hybridization; D010212:Papilloma / Q000235:genetics*