Patients asking about APOE gene test results? Here’s what to tell them

Vignette 3

Audrey S is a 60-year-old African American woman who comes to the clinic for her annual visit. Because her father had AD, she recently purchased DTC genetic testing to learn about her APOE genotype and risk for AD. Her results are ε3/ε4. She is wondering what this may mean for her future.

Lack of diversity in research cohorts often limits the generalizability of estimates. For example, both the frequency and impact of APOE ε4 differ across racial groups.¹⁸ But most of the data on APOE lifetime risk estimates are from largely White patient samples. While APOE ε4 seems to confer increased risk for AD across sociocultural groups, these effects may be attenuated in African American and Hispanic populations.^19,20 If Ms. S is interested in numeric risk estimates, the physician can provide the estimate for ε3/ε4 (20%-25% lifetime risk), with the important caveat that this estimate may not be reflective of her individual risk.

Both the frequency and impact of APOE ε4 differ across racial groups, but most of the data on APOE lifetime risk estimates are from largely White patient samples.

It may be prudent to determine whether Ms. S, at age 60, has subjective memory concerns and if she does, to perform a brief cognitive exam to serve as a baseline for future evaluations. Additionally, while the Genetic Information Nondiscrimination Act (GINA, 2008) prohibits health insurers and employers from discriminating based on genetic testing results, no legal provisions exist regarding long-term care, disability, or life insurance. Documented conversations about APOE test results in the medical record may become part of patients’ applications for these insurance products, and physicians should be cautious before documenting such discussions in the medical record.

Vignette 4

Tina L, age 60, comes to the clinic for a routine wellness visit. She recently developed an interest in genealogy and purchased a DNA testing kit to learn more about her family tree. As part of this testing, she unexpectedly learned that she has an APOE ε4/ε4 genotype. She describes feeling distraught and anxious about what the result means for her future.

Ms. L’s reaction to receiving unexpected genetic results highlights a concern of DTC APOE testing. Her experience is quite different from individuals undergoing medically recommended genetic testing or those who are participating in research studies. They receive comprehensive pre-test counseling by licensed genetic counselors. The counseling includes psychological assessment, education, and discussion of expectations.²

In Ms. L’s case, it may be helpful to explain the limits of APOE lifetime risk estimates (see Vignettes 1-3). But it’s also important to address her concerns. There are behavior scales that can aid the assessment and monitoring of an individual’s well-being. The Impact of Genetic Testing for Alzheimer’s Disease (IGT-AD) scale is a tool that assesses psychological impact. It can help physicians to identify, monitor, and address concerns.²¹ Other useful tools include the Patient Health Questionnaire-9 (PHQ-9) and the Geriatric Depression Scale (GDS) for depression, and a suicide or self-harm assessment.^2,22,23 Finally, a follow-up visit at 2 to 4 weeks may be useful to reassess psychological well-being.

Vignette 4 (cont’d)

Ms. L returns to the clinic 2 weeks later, reporting continued anxiety about her APOE test result and feelings of hopelessness and despair.

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