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Is Your Genetic Test Telling You the Truth?

Genetics

By Barbara Curtis

When I first ordered my at-home DNA testing kit, I was curious about my family’s ancestry – was the lavish rumor true that my Polish roots began with a bankrupted Hungarian royal? Although doubtful, my results showed a smidge of Hungarian in my DNA; just enough evidence to let the tale live on.

But when the option came to “upgrade” my kit to include genetic health information, another story came to mind: the struggle of a family member who was not only twice diagnosed with breast cancer – once under the age of 50 – but who was diagnosed with ovarian cancer, too.

With a click of bravery, I upgraded my kit to see if there were indicators of the BRCA1 or BRCA2 mutation, a well-known cancer gene that significantly increases the risk of developing breast, ovarian, and other cancers in both men and women.

I felt a wave of relief when I opened my results: No BRCA mutations found. As I read the details, though, I learned that my kit was only able to test for three variants of the mutation, when in fact hundreds of mutations in the BRCA genes have been identified (many of which researchers just don’t know much about just yet). So, in reality, I wasn’t in the clear. As I’ve come to understand, direct-to-consumer (DTC) genetic testing kits can unintentionally provide a false sense of security (or anxiety) since its reporting cannot tell a complete story.

BRCA1 and BRCA2 are not the only cancer genes. Mutations in many other genes also increase the risk of breast and other cancers. These other genes are also important in understanding your risk. Families with Lynch syndrome, for example, have an increased risk of ovarian, colon, and uterine cancer due to non-BRCA genes,” Susan Domchek, MD, executive director of Penn Medicine’s Basser Center for BRCA, wrote in an op-ed published in STAT News earlier this year.

There are a host of genetic, familial, and lifestyle risk factors that impact an individual’s personal risk for cancer – information a DTC test often cannot provide.

That’s where professionals like Nick Jensen, MS, LCGC, a genetic counselor at the Abramson Cancer Center at Chester County Hospital, come in. “My job is to look at the full picture by discussing the individual’s personal and family history to see if there is a genetic predisposition to certain cancers, and then to help navigate the world of testing to see what can be offered and what is right for the individual patient.”

Jensen provides pre- and post-test counseling for his patients, so they fully understand the insights genetic testing can provide, the results of their tests, and possible next steps – whether that means increased precautionary screenings or a consultation with an oncologist for more aggressive prevention.

DTC testing is not only limited in the comprehensiveness of its reporting; a recent study published in Genetics in Medicine found that 40 percent of gene variants analyzed turned out to be false positives when tested in a laboratory.

Stories of inaccurate results are also popping up online, including a woman who used a third-party DNA analysis company to further learn about her DTC results. When her online report showed alarming information, she and her husband began rethinking their life plans. After scheduling an appointment with a clinical genetic counselor and having additional testing done, she learned that her DTC results had produced a false positive and she was actually in the clear for any genetic mutations.

Since DTC’s are still relatively new and only one is currently FDA approved, there isn’t much data available to confirm how many customers have follow up testing or meet with a genetic counselor once they receive their results. However, there is concern among clinicians that some may react too quickly with the little information they receive or may not follow up with medical professionals fast enough.

“We’re seeing a guy in a couple of weeks who through his work was offered a genetic test for $9.00... and it turns out he has a mutation in a gene that causes hereditary colon cancer,” Dana Farengo Clark, MS, LCGC, a genetic counselor at the Abramson Cancer Center, said in an interview with WHYY.

The individual she spoke of had his test results for a year.

“It’s concerning because this guy is sitting on a gene that causes an 80 percent risk for colon cancer. If you’ve got this mutation, you need a colonoscopy every year and he’s already now 15 years overdue for his first colonoscopy,” she added.

Still, at-home testing may be a draw for those who know they have a serious family risk but do not have close access to genetic counseling. Fortunately, telemedicine is helping to narrow that gap.

In a recent study from the Basser Center for BRCA, researchers found that 77 percent of patients who did not have access to genetics counseling through their local providers would participate in phone or video counseling sessions remotely before moving forward with testing.

“The data definitively show the impact of remote genetic services, and it’s clear from this study that this telemedicine approach improves on what community practices can do on their own,” said study author Angela R. Bradbury, MD, an assistant professor Hematology-Oncology. “The data confirm that some people in community practices are getting testing without going through counseling first, and previous studies have shown that patients have lower levels of knowledge and lower satisfaction when that happens.”

So, while do-it-yourself ancestry tests can help keep fun fables alive for generations (like mine), with so much misinformation and unknowns about genetic variants, interpreting genetic health information may be best left to professionals.

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This blog is written and produced by Penn Medicine’s Department of Communications. Subscribe to our mailing list to receive an e-mail notification when new content goes live!

Views expressed are those of the author or other attributed individual and do not necessarily represent the official opinion of the related Department(s), University of Pennsylvania Health System (Penn Medicine), or the University of Pennsylvania, unless explicitly stated with the authority to do so.

Health information is provided for educational purposes and should not be used as a source of personal medical advice.

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