title: Early-onset Alzheimer's disease in Scotland: environmental and familial factors.
abstract: BACKGROUND
  Alzheimer's disease (AD) is a common, complex, age-related disorder in which both genetic and environmental factors are important.
  
  
  OBJECTIVE
  To integrate recent studies on genetic and environmental factors in AD into a multi-factorial disease model.
  
  
  METHODS
  Disease models to explain gene-environment interaction in cardiovascular disease are related to observations on AD.
  
  
  RESULTS
  Informative, community-based studies on the genetic epidemiology of AD are rare. Putative risk factors from the Scottish studies include increased paternal age in AD men and coal mining as paternal occupation in both AD and vascular dementia. Migration effects suggest that environmental factors in high-incidence AD areas are important during adult life.
  
  
  CONCLUSIONS
  The studies summarised do not provide sufficient data to support a single comprehensive disease model of gene-environment interaction in AD. Future studies will require very large (> or = 600) sample sizes, molecular genetic analysis, and environmental data that span neurodevelopment and the period between disease onset and appearance of clinical symptoms.
authors: Department of Mental Health, Medical School, University of Aberdeen, Aberdeen AB25 2ZD, UK.
authors: L J
authors: LJ
authors: Whalley
mesh_terms: D000367:Age Factors; D000544:Alzheimer Disease / Q000453:epidemiology / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics*; D005190:Family / Q000523:psychology; D006801:Humans; D008962:Models, Theoretical; D011110:Polymorphism, Genetic; D012307:Risk Factors; D012606:Scotland / Q000453:epidemiology; D012923:Social Class
chemical_list: D001057:Apolipoproteins E