Rationale for Correct Answer

The correct answer is: Marjorie is asymptomatic. ApoE testing is not recommended

ApoE testing is not recommended to determine the likelihood of developing LOAD. The presence of the gene is neither necessary nor sufficient to develop LOAD. It is a susceptibility risk gene, not a predictive gene.1,2

Recruitment for clinical trials based on ApoE4 status is increasing. ApoE can be used as an enrichment strategy or inclusion criteria for AD prevention trials. For example, the Alzheimer’s Prevention Initiative (API) Generation Study enrolled cognitively unimpaired participants aged 60 to 75 years with 1 or 2 ApoE4 alleles to participate in two phase 2/3 trials to test the effectiveness of 2 investigational treatments, umibecestat, and CAD106 in reducing the likelihood of developing AD.3,4

Providing and obtaining informed consent for genetic tests can be challenging. Tests for decisional capacity are available, and an online decision aid has been developed and validated for individuals considering undergoing ApoE testing.5

References:
1. American College of Medical Genetics and Genomics. (2015). Accessed March 5, 2023. https://www.choosingwisely.org/societies/american-college-of-medical-genetics-and-genomics/;
2. Knopman DS et al. Neurology. 2001;56:1143-1153.
3. Lopez C et al. Alzheimers Dement (N Y). 2019;5:216-227.
4. Ryan MM et al. Dis Assoc Disord. 2021;35:141-147.
5. Roberts JS et al. Neurobiol Dis. 2020;141:104871.