Influence of the amyloid precursor protein locus on dementia in Down syndrome.
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.
Margallo-Lana
M
M
Institute for Ageing and Health, Newcastle, UK.
Morris
C M
CM
Gibson
A M
AM
Tan
A L
AL
Kay
D W K
DW
Tyrer
S P
SP
Moore
B P
BP
Ballard
C G
CG
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
D016564:Amyloid beta-Protein Precursor