title: Influence of the amyloid precursor protein locus on dementia in Down syndrome.
abstract: BACKGROUND
  The amyloid precursor protein (APP) locus on chromosome 21 influences the development of Alzheimer disease.
  
  
  METHODS
  The authors investigated the relationship between a tetranucleotide repeat on intron 7 of the APP gene and the age at onset of dementia in Down syndrome (DS).
  
  
  RESULTS
  There was a 13-year difference in the age at onset of dementia in DS associated with the number of tetranucleotide repeat alleles in APP.
  
  
  CONCLUSIONS
  APP is an important locus predicting the age at onset of dementia in people with Down syndrome.
authors.affiliation: Institute for Ageing and Health, Newcastle, UK.
authors.forename: M
authors.initials: M
authors.lastname: Margallo-Lana
authors.forename: C M
authors.initials: CM
authors.lastname: Morris
authors.forename: A M
authors.initials: AM
authors.lastname: Gibson
authors.forename: A L
authors.initials: AL
authors.lastname: Tan
authors.forename: D W K
authors.initials: DW
authors.lastname: Kay
authors.forename: S P
authors.initials: SP
authors.lastname: Tyrer
authors.forename: B P
authors.initials: BP
authors.lastname: Moore
authors.forename: C G
authors.initials: CG
authors.lastname: Ballard
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000483:Alleles; D000544:Alzheimer Disease / Q000235:genetics; D016564:Amyloid beta-Protein Precursor / Q000235:genetics*; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D003704:Dementia / Q000453:epidemiology / Q000235:genetics*; D004314:Down Syndrome / Q000235:genetics* / Q000401:mortality / Q000523:psychology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007438:Introns / Q000235:genetics; D015993:Life Tables; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D016019:Survival Analysis
chemical_list: D016564:Amyloid beta-Protein Precursor