What A Home Genetic Test Can & Can't Tell You About Your Health

Photographed by Megan Madden.
At first, taking a home genetic test seems fun, like having your birth chart analyzed or seeing a medium. All you have to do is pay $200 or so, ship your saliva off to a company, and they'll reveal information you never knew about yourself. But some of this data can be charged and sensitive, especially when it comes to your health and well-being, which is why some health experts aren't so down with direct-to-consumer kits.
The main criticism that people have with these types of tests (never mind the fact that companies can do what they please with your genetic information once you opt in)? Home genetic tests are not meant to be a diagnostic tool, they're just intended for educational purposes, but not everyone understands that. And although companies try to present the results in a clear and digestible way, people are still left to parse through very complex genomic data. Without a genetic counselor there to help interpret the results and explain how they fit into a person's larger medical history, people may feel anxious over something that they otherwise wouldn't know about. For example, if you found out your DNA contains a variant for late-onset Alzheimer's disease, that could certainly lead to decades of anxiety for some people. So, the question becomes, if a home genetic test is not able to diagnose an illness, then what can a genetic test tell you?
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For starters, many home genetic tests work by extracting DNA from saliva and analyzing it through a process called genotyping. Basically, the test is spot-checking your DNA for certain patterns or letters within a genome that are associated with various diseases and conditions. From the results, you can learn whether you're a carrier for a genetic condition, or whether your DNA contains a variant that is associated with a particular condition — but again, it's not a replacement for a diagnostic test. You can then choose to take that information to your doctor, who can confirm the results through more clinical testing, or you can just stress out about it.

While people are getting super enthusiastic and excited — which is wonderful — I think they’re being swept up by not totally understanding that the information they’re getting really isn’t diagnostic, and really can’t be used for their medical management.

Natalie Beck, MGC, CGC, senior genetic counselor at Johns Hopkins Institute of Genetic Medicine
Whenever you get results back from a medical test it can be anxiety-provoking, but people tend to get very shook when they learn that something is different in their DNA, says Natalie Beck, MGC, CGC, senior genetic counselor at Johns Hopkins Institute of Genetic Medicine. "In reality, we all have variations in our DNA, and many times they're just normal differences that might be medically relevant," she says. And relevance is key here: Part of a genetic counselor's job from the get-go is to help figure out which tests are even necessary for an individual based on their medical history, because there's no such thing as a "one-size-fits-all test," she says. For example, if BRCA 1 and 2 genes (two genes that are associated with an increased risk of breast and ovarian cancer) are known to run in your family, then you could have targeted testing for the exact same variant. But opting into a random home test could leave you with "basically a lot of raw unvalidated information, that in many cases doesn’t mean anything," she says.
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A genetic counselor, on the other hand, can help patients think through how they're going to feel with the possible outcomes from any test, Beck says. "By the time they decide to do a test, they're actually prepared to see different types of results," she says. But home genetic tests aren't tailored to your medical history, and in isolation, it can be harder to make sense of the findings. "So, they're potentially giving patients a long list of small regions of their genome that might have small variations, but there's no next step," she says.
Having a "next step" is important, not only for your peace of mind, but also so you can take the steps necessary for your health. For this reason, a home genetic test is not the best option for certain people. "If there's an individual that's searching for a diagnosis, or has concerning family history, this isn't going to be the test that's going to answer those questions for them," says Stacey Detweiler, MS, LCGC, medical affairs associate and genetic counselor at 23andMe. At 23andme, they try to make the "next steps" clear to users, by providing a printable version of results to take to a doctor, and including a link to the National Society of Genetic Counselors so users can find a genetic counselor. "Ultimately, we want to give you the information that is to the point where this could eventually lead to a diagnosis," she says. "We want to make sure we're leading you in the right direction."
Home genetic tests are not completely bad, and there are plenty of stories about people who opted into a genetic test and ended up learning something very beneficial about their health. It's also a net positive that people are eager to learn information about their genes. "While people are getting super enthusiastic and excited — which is wonderful — I think they’re being swept up by not totally understanding that the information they’re getting really isn’t diagnostic, and really can’t be used for their medical management," Beck says. "And so, I'm concerned about people making inappropriate health decisions based on those types of results."
But as long as you understand that the test isn't a diagnostic tool, and that once you take it the company will have information about your genes to do what they want with it, it's your call whether or not you choose to ship off your spit, Beck says. "As long as [potential users] have information before they decide, then that's the most important thing."
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