title: Molecular genetic studies of chromosome 11 and chromosome 22q DNA sequences in pediatric medulloblastomas.
abstract: Medulloblastomas are primitive neuroectodermal tumors (PNETs) of the cerebellum with poorly understood pathogenesis. Previous molecular studies suggested a role for loci on chromosome 11 in the development of medulloblastomas-PNETs. In order to identify the frequency of loss and eventually the extent of allelic loss on chromosome 11, we have examined 23 pediatric medulloblastomas for loss of heterozygosity (LOH) with 16 polymorphic microsatellites. Our data reveal that LOH on 11p or 11q occurs rarely (13%) suggesting the unlikely involvement of chromosome 11 in most cases of medulloblastomas. The same frequency of LOH in medulloblastomas was detected using 8 microsatellites on 22q. Alterations of microsatellite length were found in only 4/594 PCR analyses using 28 markers located on chromosomes 2, 9, 11, 18, and 22, demonstrating that genomic instability is uncommon in medulloblastomas.
authors.affiliation: Unité 383 INSERM Clinique Lamy, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Lescop
authors.forename: A
authors.initials: A
authors.lastname: Lellouch-Tubiana
authors.forename: G
authors.initials: G
authors.lastname: Vassal
authors.forename: C
authors.initials: C
authors.lastname: Besnard-Guerin
mesh_terms: D002528:Cerebellar Neoplasms / Q000235:genetics*; D002675:Child, Preschool; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics*; D006801:Humans; D019656:Loss of Heterozygosity; D008527:Medulloblastoma / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics; D008967:Molecular Biology / Q000379:methods
chemical_list: D004273:DNA, Neoplasm