title: PSEN1 polymorphisms alter the rate of cognitive decline in sporadic Alzheimer's disease patients.
abstract: Mutations in amyloid precursor protein (APP) and presenilin (PSEN) genes are known to cause familial early-onset Alzheimer's disease (AD), which account for around 5% of AD cases. Genetic associations for the remaining "sporadic" cases, other than the risks associated with the apolipoprotein (APOE) epsilon4 allele are currently not fully established. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) in PSEN1 are associated with a modified risk for sporadic AD or a modified disease phenotype. Eight tag SNPs were identified using linkage disequilibrium (LD) data from the International HapMap project providing coverage of the entire PSEN1 gene. These SNPs were investigated for AD susceptibility in a case-control haplotype association study (N=714) and for genotype-specific effects on cognitive performance in AD patients (N=169) using non-linear mixed effects modelling. Replication of a mild associated-risk of an intronic PSEN1 polymorphism with AD was achieved (P=0.03). No other single SNPs or haplotypes were associated with AD risk. However, 3 SNPs were associated with an altered rate of cognitive decline underlining their role as genetic modifiers of disease.
authors.affiliation: Division of Clinical Chemistry, Institute of Genetics, Queen's Medical Centre, University of Nottingham, NG7 2UH, UK.
authors.forename: Olivia
authors.initials: O
authors.lastname: Belbin
authors.forename: Helen
authors.initials: H
authors.lastname: Beaumont
authors.forename: Donald
authors.initials: D
authors.lastname: Warden
authors.forename: A David
authors.initials: AD
authors.lastname: Smith
authors.forename: Noor
authors.initials: N
authors.lastname: Kalsheker
authors.forename: Kevin
authors.initials: K
authors.lastname: Morgan
mesh_terms: D017668:Age of Onset; D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology / Q000235:genetics*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000453:epidemiology / Q000235:genetics*; D018450:Disease Progression; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008957:Models, Genetic; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D053764:Presenilin-1 / Q000235:genetics*; D011569:Psychiatric Status Rating Scales; D013997:Time Factors
chemical_list: C508853:PSEN1 protein, human; D053764:Presenilin-1