APOE and early-onset autosomal dominant Alzheimer disease: ,8 In the absence of longitudinal data, individuals with high risk for late-onset Alzheimer’s disease based on the ε4-allele of the apolipoprotein (APOE) gene are a good model to test the diagnostic sensitivity of cognitive tests because they are more likely than ε3ε3 carriers to develop the disease, exhibit Alzheimer’s disease pathology at an earlier point in time and decline at a more rapid rate.9–15