At-home genetic tests should be interpreted only by experts

In 1956, Greyhound bus lines advertisements advised, “Go Greyhound and leave the driving to us!” Well, today, that sentiment applies to direct-toconsumer genetic tests for disease risks: For reliable advice, please leave the interpretation to the experts.

In a recent study published in Nature, researchers reported that up to 40 percent of DTC genetic tests provide incorrect readings in their raw data.

Now, finding that you’re part Latvian can be an interesting tidbit of information garnered from an ancestry website, but if you’re sending out a DNA sample to find out if you have the BRCA1 or BRCA2 gene -- hereditary markers for breast and/ or ovarian cancer -- you don’t want faulty results. And even though the Food and Drug Administration currently prohibits most DTC companies from offering diagnostic genetic tests, the researchers point out that some give customers their raw genotyping data upon request. The bottom line: Most DTC genetic tests are not approved by the FDA for diagnosis of disease risk, and shouldn’t be considered diagnostic! As for the companies that are approved to offer DTC diagnostic tests (23andMe), they’re authorized to report on only a limited number of genetic risk factors, two of more than 20 for BRCA variants, for example. Other gene sequences that you have which might influence those risk factors are not part of their equation. However, diagnostic tests done reliably in specialized labs generally analyze the full-coding sequences of all genes associated with a disease. So when it comes to analyzing your DNA for disease risks, leave the driving to the experts!

Mehmet Oz, M.D. is host of “The Dr. Oz Show,” and Mike Roizen, M.D. is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic. To live your healthiest, tune into “The Dr. Oz Show” or

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