How accurate are at-home DNA tests at detecting medical risks?

CHARLOTTE, NC — At-home DNA test kits can track your family’s ancestry and help you learn about yourself.

One test kit can even alert users to serious, life-threatening medical risks like breast cancer. However, WSB-TV's sister station in Charlotte, North Carolina, Channel 9, investigated and found the test may not reveal the true threat of cancer for everyone.

Last March, 23andMe received approval from the Food and Drug Administration to offer kits that can test for gene mutations, known as BRCA1 and BRCA2. They’re associated with higher risks for breast, ovarian and prostate cancer.

Channel 9 found, though, that one local mother whose test came back negative is BRCA positive.

Kelly Kashmer documented her at-home genetic test. She sent her saliva containing her DNA off in the mail to 23andMe, the only company with FDA approval for a direct-to-consumer genetic test for cancer risk.

Kashmer already knew she carried the genetic mutation for a higher risk of breast cancer but decided to try the at-home kit, curious about its effectiveness.

“This is what my eyes were drawn to here. Zero variance detected,” Kashmer said.

“I tested negative for the BRCA mutation,” Kashmer said. “But you’re BRCA positive?” Eyewitness News anchor Allison Latos asked. “I’m positive,” Kashmer replied.

Kashmer has a family history of breast and ovarian cancers. Her doctors urged her to undergo extensive genetic testing which revealed she carries the BRCA2 gene mutation.

“It means that I have an increased risk of developing breast cancer by almost 86 percent in my lifetime and 64 percent in ovarian cancer," Kashmer said.

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Not just an increased risk. Scans and other tests delivered even more devastating news. Kashmer had stage 2 triple negative breast cancer.

“It’s very aggressive. It creates its own food to feed itself. It’s a nasty cancer,” Kashmer said.

Channel 9 investigated why the at-home kit didn’t tell Kashmer she was BRCA positive.

There are more than 1,000 gene mutations that could increase a person’s risk of cancer. 23andMe only tests for three of them, which are most prevalent in people of Ashkenazi Jewish descent. That's estimated to be only 5 to 6 million people in the U.S, and Kashmer is not one of them.

“Genes are like books made up of bunches of different letters or words,” said Stacy Lenarcic, a genetic counselor at Levine Cancer Institute.

Lenarcic said at-home kits are not as thorough as clinical tests conducted by medical professionals.

“There are hundreds, if not thousands, of mutations that can be seen within these genes. So, when a patient receives a negative result for those three specific mutations, that does not mean there is not a change or mutation elsewhere in the gene,” Lenarcic said.

23andMe warns consumers of the test limitations.

A spokesperson said the company's studies show 90 percent of consumers understand, saying:

“…We are providing a genetic risk report, rather than making a diagnosis, and there are a number of environmental and lifestyle factors beyond genetics that play a role in whether or not an individual develops these conditions...

...in some cases, customers find information that they may not have found through traditional health care processes."

Before genetic testing at Atrium, Kashmer had no signs or symptoms of cancer.

“I 100 percent believe this test saved my life,” she said.

After battling 10 months of chemo and surgeries, Kashmer now celebrates five years in remission.

She worries people testing their DNA at home may not do their research, and negative results could create a false sense of security.

23andMe said it has 5 million customers in its database, but officials couldn’t say how many people received a positive result for the BRCA1 and BRCA2 gene mutations.

Genetic counselors worry people who receive a positive result from an at-home kit won’t have a medical professional there to explain their options and next steps.

Channel 9 learned insurance companies may cover genetic testing as preventative care or if you have a family history of breast or ovarian cancers.

Cox Media Group