title: APOE genotype in the diagnosis of Alzheimer's disease in patients with cognitive impairment.
abstract: BACKGROUND
  Although an association between the apolipoprotein E (APOE) ε4 allele and increased risk of Alzheimer's disease (AD) is established, the utility of APOE genotyping in the clinical diagnosis of AD is still under investigation.
  
  
  METHODS
  Medical records of 89 patients with cognitive impairment and APOE genotype data underwent a retrospective review.
  
  
  RESULTS
  Comparison of age, age at onset, education, Mini-Mental State Examination, months of follow-up, and family history of dementia did not reveal statistical difference among the patients with different APOE genotypes. The APOE ε4 carriers had a higher percentage of AD diagnoses after a median 16 months follow-up than non-APOE ε4 carriers. The APOE ε4 designation had a high sensitivity and high positive predictive value for the diagnosis of AD but a low negative predictive value and specificity.
  
  
  CONCLUSIONS
  The APOE genotyping may be helpful in diagnosing AD especially in patients presenting with atypical features or early age of onset of dementia.
authors: Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29403, USA. xns@musc.edu
authors: Xiaoyan
authors: X
authors: Sun
authors: Joyce
authors: J
authors: Nicholas
authors: Aljoeson
authors: A
authors: Walker
authors: Mark T
authors: MT
authors: Wagner
authors: David
authors: D
authors: Bachman
mesh_terms: D017668:Age of Onset; D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000235:genetics*; D053327:Apolipoprotein E4 / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D053327:Apolipoprotein E4; D001057:Apolipoproteins E