Cortical and cerebrovascular amyloid-? (A?) deposition is a hallmark of Alzheimer's disease (AD), but also occurs in elderly people not affected by dementia. The apolipoprotein E (APOE) e4 is a major genetic modulator of A? deposition and AD risk. Variants of the amyloid-? protein precursor (A?PP) gene have been reported to contribute to AD and cerebral amyloid angiopathy (CAA). We analyzed the role of APOE and A?PP variants in cortical and cerebrovascular A? deposition, and neuropathologically verified AD (based on modified NIA-RI criteria) in a population-based autopsy sample of Finns aged = 85 years (Vantaa85 + Study; n = 282). Our updated analysis of APOE showed strong associations of the e4 allele with cortical (p = 4.91 ? 10-17) and cerebrovascular (p = 9.87 ? 10-11) A? deposition as well as with NIA-RI AD (p = 1.62 ? 10-8). We also analyzed 60 single nucleotide polymorphisms (SNPs) at the A?PP locus. In single SNP or haplotype analyses there were no statistically significant A?PP locus associations with cortical or cerebrovascular A? deposition or with NIA-RI AD. We sequenced the promoter of the A?PP gene in 40 subjects with very high A? deposition, but none of these subjects had any of the previously reported or novel AD-associated mutations. These results suggest that cortical and cerebrovascular A? depositions are useful quantitative traits for genetic studies, as highlighted by the strong associations with the APOE e4 variant. Promoter mutations or common allelic variation in the A?PP gene do not have a major contribution to cortical or cerebrovascular A? deposition, or very late-onset AD in this Finnish population based study.
Cites: Nat Genet. 2009 Oct;41(10):1088-9319734902
Cites: CNS Neurol Disord Drug Targets. 2009 Mar;8(1):16-3019275634