Live Well
Jul 20th 2018

At-Home Genetic Testing Kits: What They Don’t Tell You

If you’ve ever wanted to do a genetic test, take your pick: There are about 75,000 of them, and 10 more enter the market every day, according to a new study in Health Affairs.

You can even take some at home — from a prenatal test that shows your baby’s sex to one that can detect a DNA mutation (called BRCA) known to increase your lifetime risk of breast cancer. Spit in a tube, ship it out and you can get your results in a matter of weeks.

The Downside of At-Home Genetic Testing

But in all the hype of these tests, especially the BRCA one, 23andMe, that just got Food and Drug Administration approval this spring, it begs the question: Should you really put something as serious as your genetic history in the fate of a box delivered to your door?

Kiley Delgado, MS, a certified genetic counselor at Lahey Medical Center, Peabody, says there is a lot more to consider.

“These home kits are becoming more popular because people are curious about their health,” she said. “It’s cheap, and it’s easy, but there is a lot of room for customer misinterpretation. Most people don’t realize that the reason it’s cheap is because these labs only look for specific mutations. It’s not a comprehensive test; it’s more like they’re just spot checking.”

Take the 23andMe BRCA test for instance, she added. Out of more than 1,000 BRCA mutations, it only looks for the three most common ones, which are mostly seen in people with Ashkenazi Jewish heritage.

“People don’t realize that this is all the test checks for, and that these mutations aren’t commonly seen in the non-Ashkenazi Jewish population,” she said. “So people who aren’t Jewish might take this, get a negative result, and think, ‘Oh, I don’t have the mutation,’ when that might not be the case.”

The Upside of Testing at the Office

Whereas, she said, if you get genetic testing ordered by a genetic counselor, it’s much more comprehensive — and you’ll get the benefit of pre-test genetic counseling with a face-to-face opportunity to thoroughly discuss potential risks and limitations to testing. Topics that genetic counselors discuss with each patient include testing options, possible insurance discrimination, the emotional impact that results may have on the patient and their family, as well as allowing patients to ask questions about their results.

“The national labs that genetic counselors use do full gene sequencing

,
deletion/duplication testing, and confirmation testing,” she said. “For some of these conditions, just because you have a mutation, it doesn’t mean you’re definitely going to get that disease. If you do a genetic test in the clinical setting, you’re getting that education piece up front that you wouldn’t have otherwise.”

You might think all that ends up costing a lot more, but it doesn’t really — at least not anymore.

“The price is definitely coming down,” Delgado said. “With some of these at-home kits that only screen for certain mutations, you might pay around $200, whereas some of the national labs that offer comprehensive testing are only charging $250 out of pocket.”

More Accuracy, More Education

Not only that, but you’re also getting a more accurate test, she added. A recent small-size study in Genetics in Medicine found a 40 percent false-positive rate in some of these at-home tests. One at-home lab classified 17 mutations as “increasing the patient’s risk” when comprehensive testing showed none of these were truly disease causing. Imagine being told you had a high lifetime risk for cancer, and then learning that you didn’t. Scary, right? It all links back to who has oversight and control over the raw data, Delgado said.

“The question we ask is, who is really classifying these mutations?” she said. “You have to question the accuracy; where are they getting this information? Who is in charge of maintaining the information, and how often is it updated?”

One of the topics discussed in a genetic counseling session is insurance discrimination. There are federal and state laws that make it illegal for a health insurance company to use genetic testing information as a preexisting condition. However, there are no laws that currently prohibit life, long term care, and disability insurance plans from using genetic testing information to determine coverage eligibility. Some individuals want to look into making changes to these plans before genetic testing is done. It is important to spend time with each patient to determine when the right time is for testing.

What to Do With a Positive At-Home Result

If you’ve already taken an at-home test with a positive result, Delgado recommends you contact a genetic counselor as soon as possible. The best thing to do is to just start from scratch.

“We’ll talk about those conditions the patient is most concerned about, and then do a standard session where we’ll take a full family history and retest in a clinical lab,” Delgado said. “Genetic counselors will also determine whether or not other testing is necessary.”

Most importantly, if clinical lab testing confirms a mutation, genetic counselors can help make sure patients are receiving appropriate care.

The at-home kits — while interesting to know your heritage and fun to learn about traits (like your aversion to sour taste), when it comes to health information, it’s best to let health care professionals help.

“It’s not that you should never take these at-home kits,” Delgado said. “You should just tread lightly, and know what you’re getting into.”

Do you want to talk with a genetic counselor to learn more about your testing options? Meet with the Familial Cancer Risk Assessment Center to start the conversation.

*The content on this website is for informational purposes only and is not medical advice. Please consult a physician regarding your specific medical condition, diagnosis and/or treatment.

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