Presymptomatic apolipoprotein E genotyping for Alzheimer's disease risk assessment and prevention

Current practice guidelines advocate apolipoprotein E (APOE) genotyping in cases of dementia and mild cognitive impairment and also in asymptomatic participants within the context of clinical/epidemiological research. APOE genotyping is not recommended for prognostication in cognitively intact persons outside the research arena. On the basis of emerging developments, in this article, we revisit the notion that presymptomatic APOE testing might be medically appropriate and ethical for the purpose of Alzheimer's disease (AD) risk assessment and prevention. In support of this thesis, recent evidence is adduced indicating that (i) the potency of potentially modifiable AD determinants and responsiveness to intervention may be affected by the presence or absence of the ε4 allele, (ii) disclosure of APOE status to asymptomatic individuals seeking AD risk assessment is well tolerated when appropriate safeguards are in place, and (iii) awareness of personal AD risk in general, and APOE status in particular, may motivate individuals to engage in beneficial, risk-lowering behaviors.