At-home genetics tests are proving to be a popular purchase for Americans, but there are a few things consumers should know, especially about health outlook accuracy, and so-called “surprise results’ that should factor in before whipping out a credit card.
Consumers are turning to at-home genetics testing kits that go beyond providing data on a user’s ancestry and family history and provide health-related information based on genetics. For example, genetics testing kits offer data about potential gene mutations that can put the test user – or a family member – at a higher risk of cancer.
“At-home genetic tests are popular holiday gifts that can be fun and interesting, but they also have limitations and risks — such as providing unexpected or upsetting results,” says Dani Kupperman, Genetic Counselor at Danbury Hospital, co-author of a new report on genetics testing risk, along with Jessica Lipschutz, genetic counselor at Norwalk Hospital, and Susan Ingram, also a genetic counselor at Norwalk Hospital. “Although at-home genetic testing results obtained from certified labs are usually accurate, they test for a limited selection of gene mutations and do not provide a complete picture of your health risks.”
The Danbury report follows another 2019 study from San Francisco-based Invitae that shows patients with ovarian, breast, pancreatic, prostate and colorectal cancer with potentially actionable germline variants “are being missed each year when clinicians adhere to guidelines that restrict testing to one or a few gene panels”.
"Genetic test panels that include just a few of the clinically important genes provide incomplete genetic information for patients and their clinicians, both in terms of informing treatment choices and identifying additional health risks," says Robert Nussbaum, M.D., chief medical officer of Invitae and one of the authors of the study. "Recommendations to test small numbers of genes in cancer patients date to a time when testing was much more expensive, multigene panels were not widely available, cancer risks resulting from pathogenic changes in genes other than BRCA1 or BRCA2 were not well described, and cost was prohibitive.”
According to the Danbury Hospital report, at-home genetic tests are kits that use a sample of your cells to look for changes in your DNA called gene mutations, as well as information on ancestry or paternity. “The kit provides tools and instructions for collecting a sample of your saliva, blood, or cells, usually from a swab of the inside of your cheek,” the report states. “You then send your sample to a laboratory (lab) for testing.”
The report also describes at-home genetic test results as “usually accurate” but will likely produce outcomes that are “incomplete.”
“That’s because at-home genetic tests only test for a few specific gene mutations,” the report states. “The limited scope of at-home genetic tests means that the results may not provide a complete picture of your risk for developing certain medical conditions.”
As an example of the unreliability of at-home genetics study, the Danbury study cites genetics testing reports that just test for three types of gene mutations linked to breast cancer – incorrectly, as it turns out.
“These three gene mutations are most common in people of Ashkenazi Jewish descent. For people in the general population who are not of Ashkenazi Jewish descent, the test may not capture other specific BRCA gene mutations that are linked to breast cancer risk,” the report states. “That means that it is possible for someone who receives a BRCA-negative result from an at-home genetic test to still be at an increased risk of developing breast cancer and possibly other cancers.”
As a result, at-home genetics tests can be “confusing” for users who may not be aware that, by relying in such tests, they “could be at increased risk of developing an inherited health condition.”
Problems With Main Street American Usage
Genetic testing for potential health conditions can be useful for trained health care specialists. But for average Main Street Americans – not so much, experts say.
“DNA testing is useful so long as you know how to interpret the data,” says Calloway Cook, president of Illuminate Labs, a third-party dietary supplements company. “For a layperson, some of the results can create fear.
For example, if an at-home genetics test user finds out they have a 200% increased chance of breast cancer beyond baseline, or a 300% increased risk of hypertension, it can seem really concerning, Cook says.
“Almost everyone has some genetic mutations, but what's important to keep in mind is that epigenetics (the expression of genetic code) controls the vast majority of disease risk,” he notes. “And epigenetic expression is caused by lifestyle. So eating healthy, exercising and lowering stress can literally change gene expression in favorable ways.”
The way information is presented to consumers isn’t helping either, other health care experts say.
“As a nutrigenomics specialist, I see how at-home genetics tests are overwhelming,” says Piper Gibson,
Director of Advanced Holistic Nutrition at Aria Wellness, in Los Cruces, N.M. “People reach out to me all the time asking me to help them understand their results. As a result, I’ve found that some companies will give you 12,000 pages of raw data and people don’t know how to read it all.”
Basically, no one is there to explain to them what exactly they are looking at and
what does it all means,” she adds.
Another problem - direct-to-consumer genetic tests are designed to only look at select
parts of your DNA - they are not comprehensive or examining every letter of
your genetic code, says Austin McKittrick, a certified genetic counselor at Genetic Support Foundation, in Olympia, Wash.
“This results in an immense amount of your genetics not being taken into consideration,” McKittrick says. “So, at best, you’re only getting part of the picture. These partial results are also often misunderstood by patients who believe they’ve had more comprehensive testing done.”
Conversely, just because you test ‘negative’ for a health condition on an at-home
test doesn’t mean that you have a low risk for that disease.
“23andMe (a genetic testing company) currently tests for three gene variants in the BRCA1 and BRCA2 genes that are substantially more common in individuals of Ashkenazi Jewish ancestry,” McKittrick says. “If you are not Ashkenazi Jewish and you carry a BRCA variant that increases
your risk for cancer, the 23andMe test most likely will not detect it.”
Consequently, these concepts can be difficult to understand, which is where meeting with
a specialist (such as a genetic counselor) can be helpful,” he says.
So-called “surprise results” are throwing test users some serious curveball, as well.
“Many people who do the at home genetic tests are finding out that one or both of their parents are not who they thought they were (a scenario known as non-paternity),” McKittrick adds. “Some studies have shown that non-paternity rates range from as low as 1% <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4611233/ up to as high as 30% <https://jech.bmj.com/content/59/9/749.long.”
“This can understandably cause much stress and anxiety not only for the individual but for their family. With millions of people doing ancestry testing every year, that adds up to quite a lot of people who will fall into this category,” he adds.
Even Physicians Have Problems with At-Home Genetic Testing
Worse, when at-home test takers go to their physicians, they’ll find out that many doctors don’t understand the genetic testing nor do they have the time to, Gibson says.
“Physicians are overwhelmed with patients and day to day practice,” she says. “Although this is changing, I know many people who have taken their test to their doctor and they didn't know what to do with it.”
Gibson says that if someone wants to know their genes better – and well they should - they should seek out a professional who has an understanding of testing and how it applies to the body.
“You really need someone who can explain what it all means.”