Should the average person take an at-home genetic test to assess disease risk?
The Alzheimer’s Association does not recommend genetic testing for Alzheimer's disease for the general population. Many people develop dementia due to the disease without having the Alzheimer’s risk gene identified by this [23andMe] test, and many people with the gene do not develop Alzheimer’s dementia. If someone wants to move ahead with an at-home test, we recommend genetic counseling before ordering the test and when the results are obtained.
Heather Snyder, PhD, is senior director of Medical and Scientific Operations at the Alzheimer's Association.
At-home testing is perilous for the average person. 23andMe, for instance, has a sample report on its website of a negative Alzheimer’s test result, but no example of a positive result. Providing results through a genetic counselor would be better but would raise the test price substantially. From a legal standpoint, 23andMe has disclaimers basically saying that they’re not providing health information. Then exactly what do they think they are providing?
The potential for genetics to contribute to personalized medicine is now emerging, but genetic risk may simply be a baseline for calibration of risk that includes consideration of non-genetic factors. It is also important to know why you are seeking a genetic test—curiosity, advance planning, to motivate behavioral change or care seeking, or to guide tailored interventions? Partnership with professionals to interpret results and to implement prevention strategies based on those results is essential.
M. Daniele Fallin, PhD, is chair of the Department of Mental Health and director of the Wendy Klag Center for Autism and Developmental Disabilities.
Knowing one’s genetic risk status can be very empowering—if the product actually tests for the mutation(s) it says it’s testing for and those mutations actually confer risk for the associated disease. People should understand what is being tested (individual variants versus genome sequence), the possible results (mutation positive, mutation negative, indeterminate result) and what happens to their data (does it belong to the customer or the company?).
When the FDA approved the genetic risk test [23andMe] in 2017, the agency noted that the testing can't determine a person's overall risk of developing a disease. But I think it is a good step toward increasing the public's health literacy. We need everyone to have a more nuanced and robust understanding of genetic testing upon which rational decisions and preferences can be based.
George Demetri, MD, is chair of the Science Policy and Government Affairs Committee with the American Association for Cancer Research.