Related Experiment Videos
Apolipoprotein E in Alzheimer's disease risk and case detection: a case-control study
W A Kukull1, G D Schellenberg, J D Bowen
1Department of Epidemiology, University of Washington, Seattle 98195, USA.
Journal of Clinical Epidemiology
|October 1, 1996
Summary
The apolipoprotein E4 (APOE E4) allele is a significant risk factor for Alzheimer's disease (AD). However, APOE E4 genotyping is not a reliable diagnostic test for AD, as it can miss cases and misclassify individuals.
Area of Science:
- Genetics
- Neuroscience
- Epidemiology
Background:
- Alzheimer's disease (AD) is a progressive neurodegenerative disorder.
- The apolipoprotein E gene (APOE) plays a role in lipid transport and has different alleles, including epsilon 4 (E4).
- The association between APOE E4 and AD risk is a subject of ongoing research.
Purpose of the Study:
- To investigate the association between the APOE E4 allele and Alzheimer's disease.
- To evaluate the utility of APOE E4 genotyping as a diagnostic test for AD.
Main Methods:
- A case-control study was conducted using approximately 23,000 individuals aged 60 years or older.
- Analysis included 234 Caucasian probable AD patients and 304 cognitively intact controls.
- APOE genotypes were determined from blood samples; diagnoses were confirmed through clinical examinations and medical records.
Main Results:
- Individuals with one APOE E4 allele had an odds ratio of 3.1 for AD; those with two E4 alleles had an odds ratio of 34.3.
- As an AD indicator, one E4 allele had 52% sensitivity and 74% specificity.
- The homozygous E4 genotype showed 23% sensitivity and 99% specificity for AD diagnosis.
Conclusions:
- The APOE E4 allele is a significant risk factor for Alzheimer's disease.
- APOE E4 genotyping alone is insufficient as a screening or diagnostic marker for AD due to potential misclassification of cases and controls.
- Cardiovascular disease did not confound or modify the observed APOE E4-AD association.