NEW YORK (GenomeWeb) – Now that more people are buying genetic tests from online consumer genomics firms, and learning information like their APOE4 carrier status associated with increased risk for late-onset Alzheimer's disease, it's becoming impossible for healthcare providers to ignore this trend.
Around the Thanksgiving holiday in the US, consumer genomics firms like 23andMe and Helix begin offering discounted test kits to entice people to purchase them as gifts. For example, Ancestry.com, a company that offers genetic genealogy tests but not disease risk tests, sold 1.7 million DNA kits through similar deals during the same holiday last year.
A recent statement issued by the Alzheimer’s Foundation of America's Medical, Scientific and Memory Screening Advisory Board recognized that direct-to-consumer genetic testing is happening, whether healthcare providers like it or not, and that consumers increasingly have access to tests for APOE4.
"We began with the premise that the genie is out of the bottle," said Lori Frank, a member of the AFA medical advisory board. "People are getting tested for genetic risk obviously. We wanted to be sure that attention is focused to three issues we felt rose to the top."
The advisory board is of the view that healthcare providers, industry, and genetics experts should help consumers understand these test reports, as well as address the potential for negative outcomes. For example, Frank highlighted the importance of communicating to consumers the nuances of what it means to carry and not carry an APOE4 allele and warning them about the potential for negative consequences of this information.
As a third point, the AFA believes that these interactions are also an opportunity to have a positive impact on individuals by promoting healthy behaviors and advancing research. "There is a public health good, in our view, of raising awareness so that there is more participation in research," said Frank, who is also a health and aging policy fellow with the American Political Science Association Congressional Fellows program.
Similarly, the AFA advised consumers in a press release ahead of the Thanksgiving holiday a few weeks ago that before buying one of these kits, they should consider the positive and negative effect that genetic test results about family history and disease risks can have, realize that a predisposition for a disease is not a diagnosis, and learn the privacy implications of getting tested. Importantly, the AFA further recommended that consumers speak with a genetic counselor, who can provide information on these topics and answer questions.
The AFA's statements come during a growth period for the consumer genomics industry. The US Food and Drug Administration last year authorized 23andMe's genetic health risk reports, including APOE4 testing, for direct-to-consumer sales. This year, HealthLytix and Dash Genomics launched a polygenic risk score, which uses the raw genomic data from 23andMe and Ancestry.com customers and their age to provide a risk estimate for late-onset Alzheimer's.
The online consumer genomics market place operated by Helix, meanwhile, offers consumers the opportunity to garner genetic insights in a variety of contexts, and recently began selling an APOE test from ADx Healthcare. The company already offers molecular, anatomical, and surgical pathology services, including APOE testing, that doctors can order, but embraced the consumer genomics model, recognizing that many individuals who wanted to learn their risk for late-onset Alzheimer's were often barred by their doctors' unwillingness to order testing. Through Helix, APOE testing is ordered by a physician network, not the individual's own doctor, and the service includes genetic counseling.
Though consumers can now learn their Alzheimer's risk through various consumer genomics channels, research shows that once tested, some regret the decision and experience anxiety. Although many individuals who have learned their APOE4 status have found others like them online to discuss the latest research, lifestyle issues, and food choices, one reason these support groups have formed is because the medical establishment has generally been dismissive of those who come to their doctors asking how their test results could inform their care.
Frank noted that this was part of the reason for the AFA advisory board's statement. "No matter what any individual's personal opinion is about genetic testing, people are having it done and it's available," she said. "So, how can we best support population health and optimize individual-level care?" For example, since many clinicians lack training in genetics, which in turn could lead to consumers receiving varying advice about how to interpret test results and what actions to take, the AFA's advisory board recommends advancing standardized information systems.
While AFA's statement focuses on what healthcare providers and other stakeholders in the field should be doing now that consumer genomics has become more commonplace, with companies advertising their services on the radio and TV, other organizations remain unconvinced about the value of DTC testing and advise consumers not to buy these tests, especially without genetic counseling support.
The 2011 joint guidelines from the American College of Medical Genetics and Genomics and the National Society of Genetic Counselors, for example, explicitly advise against DTC testing of APOE variants and note that testing should be accompanied by genetic counseling. After the FDA authorized 23andMe's genetic health risk reports last year, which are offered DTC without counseling support, the ACMG expressed particular concern that consumers may be at risk of gaining an incomplete picture of their genetic predisposition for serious diseases, such as Alzheimer's, and that the results may fuel follow-on testing or inspire self-directed changes.
The Alzheimer's Association also advises against routine genetic testing for Alzheimer's risk without counseling. Last year, the association updated its statement on genetic testing after 23andMe received FDA authorization for its disease risk reports, to inform consumers that just because a person learns they don't carry an APOE4 allele through such as service, this doesn't mean they won't develop Alzheimer's. And if they do find out they are carriers, it still doesn't mean they definitely will develop the disease.
"Frankly, the science isn't far enough along with APOE4 in terms of what it means and how it should guide a person's care for it to be useful in medical care," said Keith Fargo, director of scientific programs and outreach at the Alzheimer's Association. "We don't know what to do with that information for people if they have APOE4 versus if they don't have APOE4."
While the companies marketing APOE testing directly to consumers highlight that learning one's APOE4 status early enough could motivate one to lead a healthier lifestyle, which in turn could have some positive impact on one's brain health, many experts aren’t convinced. "Exercising more; eating a healthy, balanced diet; and making sure you stay cognitively engaged are all things people should be doing whether they have one, two, or zero copies of APOE4," Fargo said.
In the general population, between 10 percent and 15 percent of people will get late-onset Alzheimer's by age 85, but those with one or two copies of the APOE4 version of the gene have a greater lifetime risk of getting the disease, and at a younger age. It is commonly estimated that having one copy of the APOE4 allele can increase one's lifetime risk for the disease by three times compared to the general population and having two copies increases the risk 12-fold.
However, Fargo pointed out that the lifetime risk estimates associated with APOE4 are drawn from studies of cohorts from National Alzheimer's Coordinating Centers around the country. Since individuals in these studies are more likely to have a family history of Alzheimer's, the risk estimates that come from that data set may be higher than if the studies involved a random sampling of the population.
"We don't even really know enough to tell people what their risk actually is based on these genetic test results, let alone have that information guide their medical treatment or their personal approach to their health," Fargo said.
This is perhaps why the AFA highlights the opportunity for advancing research within its statement about DTC genetic testing. Despite the hefty funds poured into Alzheimer's research over the years, there is still no drug to slow or stop the cognitive decline that results from the disease, and there are no definitive preventive measures.
However, according to Wes Ashford, chairman of AFA’s medical advisory board, consumer testing is having a positive impact in terms of informing people about genetics and getting them more interested in partaking in research. For example, 23andMe and Helix's strategy to partner with researchers to offer participants test kits for free has proven to be a successful recruitment tool.
These types of approaches could also potentially advance Alzheimer's research in new directions. "I still hear people talk about the amyloid hypothesis. It's very much related to the underlying disease process but it's not in the causal chain of dementia," Ashford said. "We've been having big arguments about this in the scientific community for 25 years and amyloid has overshadowed APOE, which is where I think we have to go to solve Alzheimer's disease."
Meanwhile, the National Institute on Aging has convened a working group that is thinking about how information on biomarkers and genetic test results should be disclosed to people, whether testing happens within the healthcare system or through DTC channels. "There are a number of issues that the community is trying to wrap its arms around right now," said Fargo, a member of the committee, such as what doctors should tell people who want to get tested for Alzheimer's and dementia biomarkers, and what to tell those who have already gotten tested.