The Food and Drug Administration recently authorized 23andMe to provide consumers with results of germline DNA sequence variants associated with risk for 10 health conditions, among them hereditary hemochromatosis, alpha-1 antitrypsin deficiency, celiac disease, Alzheimer’s disease, and Parkinson’s disease. After they submit a saliva sample and pay a test fee, customers ordering the online test will receive a report delineating their ancestry markers and informing them whether they carry any of the genetic variants associated with selected health risks included on the targeted DNA sequencing panel.The FDA initially had issued a warning to 23andMe preventing them from including information about health risks on these direct-to-consumer (DTC) test reports. However, the current DTC test appears to meet the FDA’s requirements for test accuracy and reproducibility. Yet, it is important to note that the FDA’s authorization is not an endorsement of the validity or clinical utility of DTC health risk tests, which simply analyze whether an individual’s DNA carries a genetic variant associated with “increased” risk for the condition in question. In fact, the American College of Medical Genetics warns that DTC genetic tests, which interpret genomic information in the absence of individuals’ clinical and family history, have the potential to be misleading for both clinicians and patients, resulting in unnecessary worry and/or additional testing. When examining results of DTC health risk tests, the following truths should be self-evident: First, being a carrier of a genetic marker associated with a disease does not mean that a person has the disease or will necessarily ever develop the disease. Second, a negative DTC genetic test result does not exclude the disease.
As more consumers partake in “recreational genomic testing,” clinicians should understand the limitations of DTC genetic tests and should be prepared to discuss with patients why these should not supersede clinical diagnostic evaluations.
Dr. Stoffel is a gastroenterologist, assistant professor of internal medicine, and director of the cancer genetics clinic at the University of Michigan, Ann Arbor. She has no disclosures.