title: Variants of CYP46A1 may interact with age and APOE to influence CSF Abeta42 levels in Alzheimer's disease.
abstract: Recent studies have suggested that variants of CYP46A1, encoding cholesterol 24-hydroxylase (CYP46), confer risk for Alzheimer's disease (AD), a prospect substantiated by evidence of genetic association from several quantitative traits related to AD pathology, including cerebrospinal fluid (CSF) levels of the 42 amino-acid cleavage product of beta-amyloid (Abeta42) and the tau protein. In the present study, these claims have been explored by the genotyping of previously associated markers in CYP46A1 in three independent northern European case-control series encompassing 1323 individuals and including approximately 400 patients with measurements of CSF Abeta42 and phospho-tau protein levels. Tests of association in case-control models revealed limited evidence that CYP46A1 variants contributed to AD risk across these samples. However, models testing for potential effects upon CSF measures suggested a possible interaction of an intronic marker (rs754203) with age and APOE genotype. In stratified analyses, significant effects were evident that were restricted to elderly APOE epsilon4 carriers for both CSF Abeta42 ( P=0.0009) and phospho-tau ( P=0.046). Computational analyses indicate that the rs754203 marker probably does not impact the binding of regulatory factors, suggesting that other polymorphic sites underlie the observed associations. Our results provide an important independent replication of previous findings, supporting the existence of CYP46A1 sequence variants that contribute to variability in beta-amyloid metabolism.
authors.affiliation: Department of Clinical Neuroscience, Sahlgrenska University Hospital, Göteborg University, Göteborg, Sweden.
authors.forename: Annica
authors.initials: A
authors.lastname: Johansson
authors.forename: Hagit
authors.initials: H
authors.lastname: Katzov
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.forename: Lars
authors.initials: L
authors.lastname: Feuk
authors.forename: Boo
authors.initials: B
authors.lastname: Johansson
authors.forename: Nenad
authors.initials: N
authors.lastname: Bogdanovic
authors.forename: Niels
authors.initials: N
authors.lastname: Andreasen
authors.forename: Boris
authors.initials: B
authors.lastname: Lenhard
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Brookes
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Pedersen
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Prince
mesh_terms: D000367:Age Factors; D000368:Aged; D000544:Alzheimer Disease / Q000235:genetics* / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D000704:Analysis of Variance; D001057:Apolipoproteins E / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D016022:Case-Control Studies; D000072556:Cholesterol 24-Hydroxylase; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D005060:Europe; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D016415:Sequence Alignment; D013250:Steroid Hydroxylases / Q000235:genetics*; D016875:tau Proteins / Q000134:cerebrospinal fluid
chemical_list: D016229:Amyloid beta-Peptides; D001057:Apolipoproteins E; D017931:DNA Primers; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins; D013250:Steroid Hydroxylases; D000072556:Cholesterol 24-Hydroxylase