title: Genome research in pre-dementia stages of Alzheimer's disease.
abstract: Genetic characterization of individuals at risk of Alzheimer's disease (AD), i.e. people having amyloid deposits in the brain without symptoms, people suffering from subjective cognitive decline (SCD) or mild cognitive impairment (MCI), has spurred the interests of researchers. However, their pre-dementia genetic profile remains mostly unexplored. In this study, we reviewed the loci related to phenotypes of AD, MCI and SCD from literature and performed the first meta-analyses evaluating the role of apolipoprotein E (APOE) in the risk of conversion from a healthy status to MCI and SCD. For AD dementia risk, an increased number of loci have been identified; to date, 28 genes have been associated with Late Onset AD. In MCI syndrome, APOE is confirmed as a pheno-conversion factor leading from MCI to AD, and clusterin is a promising candidate. Additionally, our meta-analyses revealed APOE as genetic risk factor to convert from a healthy status to MCI [OR = 1.849 (1.587-2.153); P = 2.80  × 10-15] and to a lesser extent from healthy status to SCD [OR = 1.151 (1.015-1.304); P = 0.028]. Thus, we believe that genetic studies in longitudinal SCD and MCI series may provide new therapeutic targets and improve the existing knowledge of AD. This type of studies must be completed on healthy subjects to better understand the natural disease resistance to brain insults and neurodegeneration.
authors.affiliation: Memory Clinic of Fundació ACE,Institut Català de Neurociències Aplicades,Barcelona,Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Moreno-Grau
authors.affiliation: Memory Clinic of Fundació ACE,Institut Català de Neurociències Aplicades,Barcelona,Spain.
authors.forename: Agustín
authors.initials: A
authors.lastname: Ruiz
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology*; D015415:Biomarkers; D001921:Brain / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D060825:Cognitive Dysfunction / Q000235:genetics / Q000503:physiopathology; D003704:Dementia / Q000175:diagnosis / Q000235:genetics*; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D023281:Genomics / Q000379:methods; D006801:Humans; D040582:Inheritance Patterns; D010641:Phenotype; D040641:Quantitative Trait Loci; D012307:Risk Factors
chemical_list: D015415:Biomarkers