title: Regional brain atrophy in cognitively intact adults with a single APOE epsilon4 allele.
abstract: OBJECTIVE
  To determine whether cognitively intact adults with the APOE epsilon3/epsilon4 genotype show reduced gray matter density on voxel-based morphometry (VBM) vs those homozygous for the epsilon3 allele.
  
  
  METHODS
  Participants were healthy, cognitively intact, right-handed adults, age 19 to 80, who completed genotyping, neuropsychological testing, and MRI. Forty-nine participants had the epsilon3/epsilon3 genotype and 27 had the epsilon3/epsilon4 genotype. Gray matter data were analyzed using the general linear model as implemented in the Statistical Parametric Mapping package, adjusting for age and sex.
  
  
  RESULTS
  The epsilon3/epsilon4 participants showed lower gray matter density than the epsilon3/epsilon3 participants in right medial temporal and bilateral frontotemporal regions as well as other areas. There were no regions in which epsilon3/epsilon4 participants showed higher gray matter density than epsilon3/epsilon3 participants.
  
  
  CONCLUSIONS
  Regionally reduced gray matter density is detectable in cognitively intact adults with a single copy of the APOE epsilon4 allele.
authors.affiliation: Department of Psychiatry, Dartmouth Medical School/DHMC, Lebanon, NH 03756-0001, USA.
authors.forename: H A
authors.initials: HA
authors.lastname: Wishart
authors.forename: A J
authors.initials: AJ
authors.lastname: Saykin
authors.forename: T W
authors.initials: TW
authors.lastname: McAllister
authors.forename: L A
authors.initials: LA
authors.lastname: Rabin
authors.forename: B C
authors.initials: BC
authors.lastname: McDonald
authors.forename: L A
authors.initials: LA
authors.lastname: Flashman
authors.forename: R M
authors.initials: RM
authors.lastname: Roth
authors.forename: A C
authors.initials: AC
authors.lastname: Mamourian
authors.forename: G J
authors.initials: GJ
authors.lastname: Tsongalis
authors.forename: C H
authors.initials: CH
authors.lastname: Rhodes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics*; D001284:Atrophy / Q000175:diagnosis / Q000235:genetics; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000235:genetics; D004252:DNA Mutational Analysis; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009474:Neurons / Q000473:pathology*
chemical_list: D053327:Apolipoprotein E4; D001057:Apolipoproteins E