Genetic Testing for Alzheimer Disease-Reply

In Reply.  —We share Dr Tracy's hopes for a future in which preventive or delaying antidementia strategies are applied widely in asymptomatic individuals at higher risk for AD, which is a tremendous public health problem. However, although many exciting ideas exist about how to delay onset of AD, none are proven. Certainly prevention or a delay of onset are strategies increasingly within reach and of obvious moral and social value.¹ If some potentially AD-preventing compounds were to have adverse effects, then defining high-susceptibility subpopulations based on genetic testing would be laudable. But no link has yet been established between genotype (eg, the presence or absence of an APOE ∈4 allele) and efficacy of potential therapies.From our focus group activities, it appears that many, if not most, caregivers would proceed with a susceptibility test only if preventive or delaying compounds are better established and much more clearly related to genotype than