FDA approves DNA test for predicting drug effectiveness — if it carries warnings

The US Food and Drug Administration (FDA) has approved the first consumer pharmacogenetic test, but not without crucial caveats. 

Direct-to-consumer DNA-testing firm 23andMe have received FDA authorisation to sell their test, however it will have to carry a warning advising patients not to stop or change any medication they are taking based on the results. 

'This test…does not determine whether a medication is appropriate for a patient, does not provide medical advice and does not diagnose any health conditions. Consumers should not use this test to make treatment decisions on their own. Any medical decisions should be made only after discussing the results with a licensed health care provider and results have been confirmed using clinical pharmacogenetic testing,' said Dr Tim Stenzel, director of the Office of In Vitro Diagnostics and Radiological Health in the FDA's Centre for Devices and Radiological Health. 

Pharmacogenetic tests aim to predict how a person's DNA will affect their response to medications. 23andMe say that their new test provides information on 33 genetic variants that are associated with how consumers respond to over 50 common over-the-counter and prescription drugs, especially those for mental health. It is currently the only approved direct-to-consumer pharmacogenetic test. The company has not yet set a release date or price for the product.

Other providers already offer genetic tests for drug response, but these must be ordered by a medical professional. Despite providing the same service, they do not require FDA approval, even if the patient never meets the clinician in person. 

Robert Green, professor of medicine at Harvard Medical School and advisor to genetic testing companies Veritas and Helix, said: 'This is an area that is controversial, in the sense that some people feel there should be more interaction with the customer by a physician before a physician orders such a test.' 

'We believe it's important that all consumer genetic health tests should be going through the FDA and subject to the same rigorous testing that 23andMe undergoes,' said 23andMe CEO Anna Wojcicki. 'It is concerning that the FDA is not requiring all direct-to-consumer genetic testing services to meet the high bar for analytical validity, accuracy or user comprehension, which 23andMe does. It's confusing for consumers that this double standard exists.'