title: Meningioma in Down Syndrome.
abstract: BACKGROUND
  Down syndrome comprises multiple malformations and is due to trisomy of chromosome 21. There is epidemiologic evidence that individuals with Down syndrome are at decreased risk for solid tumors including brain tumors. It has been suggested that some genes expressed on the extra copy of chromosome 21 act as tumor suppressor genes and contribute to protection against tumorigenesis.
  
  
  METHODS
  We report the first case to our knowledge of a patient with Down syndrome, an 8-year-old boy, with an intracranial meningioma, in which the status of chromosome 21 was examined. The diagnosis was based on histologic examination of the surgically resected tumor. Postoperatively, the patient's neurologic status improved, and there was no tumor regrowth in the next 2 years. Fluorescence in situ hybridization for chromosome 22 confirmed high allele loss involving the neurofibromin 2 gene locus, a finding typical in meningiomas. Fluorescence in situ hybridization also revealed chromosome 21 heterogeneity in tumor cells; not only cells with trisomy 21 but also cells with disomy and monosomy 21 were present. All blood cells from the patient manifested trisomy 21.
  
  
  CONCLUSIONS
  Deletion of the chromosome 21 allele may be associated with tumorigenesis of meningioma in Down syndrome. This supports the hypothesis that some genes whose expression is increased on the extra copy of chromosome 21 function as tumor suppressor genes and that they contribute to the reduced tumor incidence in individuals with Down syndrome.
authors: Division of Neurosurgery, Nobeoka Hospital, Miyazaki, Japan; Department of Neurosurgery, Kumamoto University Hospital, Kumamoto, Japan.
authors: Takahiro
authors: T
authors: Yamamoto
authors: Department of Neurosurgery, Kumamoto University Hospital, Kumamoto, Japan. Electronic address: nshinojima@fc.kuh.kumamoto-u.ac.jp.
authors: Naoki
authors: N
authors: Shinojima
authors: Division of Neurosurgery, Nobeoka Hospital, Miyazaki, Japan.
authors: Tatemi
authors: T
authors: Todaka
authors: Division of Neurosurgery, Nobeoka Hospital, Miyazaki, Japan.
authors: Shigeyuki
authors: S
authors: Nishikawa
authors: Department of Neurosurgery, Kumamoto University Hospital, Kumamoto, Japan.
authors: Shigetoshi
authors: S
authors: Yano
authors: Department of Neurosurgery, Kumamoto University Hospital, Kumamoto, Japan.
authors: Jun-ichi
authors: J
authors: Kuratsu
mesh_terms: D000483:Alleles; D002648:Child; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D004314:Down Syndrome / Q000150:complications* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008579:Meningioma / Q000150:complications* / Q000473:pathology / Q000601:surgery; D025581:Neurofibromin 2 / Q000235:genetics / Q000378:metabolism
chemical_list: D025581:Neurofibromin 2
keywords: Chromosome 21; Down syndrome; Intracranial tumor; Meningioma