Why you may need a second, or even third, opinion on your genetic test results

Lynch Syndrome Knowing Your Cancer Risk Could Save Your Life x
Image credit: Heather Hampel
[Radiology resident Joshua Clayton] sent a sample of his saliva to 23andMe, the genetic testing company.

His report was pretty mundane — no new revelations. But then he sent the profile created by 23andMe to a separate company called Promethease, which promises to do a more in-depth analysis for genetic mutations that cause disease.

The news was not good. Dr. Clayton got back a report with a sinister red box at the top saying he had a mutation linked to Lynch syndrome, a frightening genetic disorder that leads to potentially deadly cancers at an early age.

…

After two weeks of panic and yet another genetic test at a company with expertise in medical diagnostics, he learned the red box result was wrong. He simply didn’t have the mutation.

…

In one small study, Ambry Genetics — a lab certified to do medical testing — looked at 49 samples sent in by physicians whose patients had been told that they had disease-causing mutations by third-party interpreters.

Ambry found that 40 percent were wrong. In addition, some genetic variations classified by second companies as threatening actually were benign.

…

Greg Lennon, a co-founder of Promethease, said that the company’s reports include a disclaimer saying the data are “not intended for medical or health purposes.” Customers are warned to seek out “an independent, clinically validated test.”

Read full, original post: The Online Gene Test Finds a Dangerous Mutation. It May Well Be Wrong.

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