Thinking About an At-Home DNA Test? Here's What Genetic Counselors Advise

At-home DNA testing kits promise to unlock the mysteries of your ancestry, health risks, and even quirky traits like your taste preferences. With more than 100 million people having taken at-home tests like AncestryDNA, 23andMe, and FamilyTreeDNA by the end of 2021, according to the American Medical Association, these kits are undeniably popular. But before you swab your cheek, here’s what genetic counselors want you to know.

1. You Might Uncover an Uncomfortable Family Secret

While learning about your heritage can be a fun and enlightening experience, it’s not always all family reunions and fresh insights. According to a 2022 survey by YouGovAmerica, about 20% of Americans have used a mail-in DNA testing service, and nearly a third of those learned about relatives they never knew existed.

This could mean discovering a second cousin you never knew about or finding out your parent isn’t who you thought they were. The latter scenario even has a name: NPE, or not parent expected, says Brianne Kirkpatrick, LGC, a spokesperson for the National Society of Genetic Counselors. "It can be really traumatic and destabilizing for people, because it shakes your whole sense of personal identity," Kirkpatrick explains.

While some surprises may be heartwarming, it’s important to prepare yourself emotionally for the possibility of unsettling revelations before diving into a DNA test.

2. Your Results Might Be Misleading

At-home DNA tests often include information on fun traits, like your likelihood of being a morning person, as well as serious health risks, such as genetic predispositions to conditions like breast cancer. However, interpreting these results correctly isn’t always straightforward.

Jessica Everett, LGC, a genetic counselor at NYU Langone Medical Center, recalls a case where a woman mistakenly thought she tested positive for three BRCA gene variants linked to increased cancer risk. "That got my attention, as it's not possible," Everett says. The woman had actually tested negative but misread the results.

Even accurate results can create a false sense of security. For example, 23andMe tests for three specific BRCA gene variants, but over 1,000 variants exist. If you don’t carry the three tested variants, it doesn’t mean you’re entirely risk-free.

A study published in Nature's Genetics in Medicine in December 2018 found that about 40% of positive results from at-home DNA tests were false positives when rechecked through clinical testing. This highlights why any significant findings from a home test should be confirmed by a medical professional.

3. At-Home Tests Aren’t as Comprehensive as Clinical Ones

When you get genetic testing through a healthcare provider, it often involves a thorough analysis of entire genes to detect a wide range of mutations. Julia Cooper, LGC, from The Ohio State University James Comprehensive Cancer Center, explains:

"It's helpful to think of our genome like a set of encyclopedias. Medical-grade tests read the entire sentence for errors, while at-home tests might only check a specific word or letter."

This means that while an at-home test might identify a specific genetic variant, it could miss other crucial mutations that impact your health. For example, a 2020 study in Nutrients found that only a third of companies offering nutrigenetic tests (tests that link genetics to nutrition) disclosed which genes they analyzed. Without this transparency, the health advice provided could be misleading or overly simplistic.

4. There Are Serious Privacy Considerations

Beyond the genetic insights, at-home DNA testing companies collect a wealth of personal information from your address and email to potentially sensitive health data.

In 2018, a breach at DNA testing company MyHeritage exposed the data of more than 92 million users, highlighting the potential risks of sharing your genetic information.

When signing up, read the fine print carefully, including sections about sharing your data with third-party research partners. While contributing to research can be a good thing, it’s important to understand that you won’t have control over how your genetic data is used once it leaves the company.

Should You Take an At-Home DNA Test?

At-home DNA tests can be a fun and educational tool, but they shouldn’t replace professional medical advice. If you do receive potentially concerning results, consult your primary care provider or a genetic counselor. They can help interpret your results accurately and guide you toward clinical-grade testing if needed.

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