DNA test kits that let people trace their ancestry have become wildly popular. Companies such as Ancestry.com, MyHeritage and 23andMe racked up record sales during the latest Christmas shopping season. TV and Internet ads promoting gene kits are ubiquitous.
More than 12 million people have had their DNA sequenced using these kits, 10 million since 2016. Some kits offer the possibility of revealing genetic markers for diseases such as Parkinson’s, Alzheimer’s and Celiac.
While some direct-to-consumer (DTC) genetic health data may be useful, there’s a danger that it will lead customers to self-diagnose and make treatment decisions without first consulting their physician.
Just two months ago, the FDA cleared 23andMe to offer, without a doctor’s order, a test for BRCA1 and/or BRCA2 genes.
Mutations in these genes indicate an increased risk for breast and ovarian cancer, and potentially others such as melanoma, prostate, and pancreatic cancer. But the test only provides information on three of the most well-understood mutations in these two genes. There are hundreds of additional mutations that can also confer cancer risk, hence a negative test result may falsely reassure patients who may forego necessary preventive interventions, or neglect signs or symptoms of cancer if present.
Health care providers may be asked to help patients understand the implications of genetic information in test results. Physicians must make diagnoses and treatments based on the information. This calls for more training and tools to cover the direct-to-consumer genetic testing landscape. Several academic medical centers have already expanded curriculums. Vanderbilt offers instruction on genetic variants contributing to disease susceptibility and how to choose among drug therapies based on genetic factors. Representatives from commercial gene-testing companies along with clinicians, genetic counselors, attorneys and other experts with specific perspectives on gene-testing participate in symposia on our campus. Students and faculty engage in sessions that focus on the beneficial health potential and possible risks of direct-to-consumer genetic test kits.
With DNA sequencing costs decreasing, genetic information is more readily available than ever before. This is a good thing. As Anne Wojcicki, CEO and co-founder of 23andMe wrote recently in STAT, making gene test results “directly available to consumers is a huge milestone in empowering people to be in control of their own health information.”
Information is important, but we have responsibility to ensure consumers understand their personal health data. To date, the biomedical community has not demonstrated that those who use DNA test kits truly benefit by having better health outcomes. For example, does knowing the presence of risk factors for a disease really improve an outcome, such as earlier cancer detection? Rather, it is possible that awareness of risk indicators unduly frightens an individual from undergoing necessary evaluation and treatment.
We just don’t know yet, hence it’s important researchers and DTC businesses demonstrate that the public’s use of DNA test kits improves patients’ health.
In this age of the quantified self, people seek as much health information as they can. It’s a natural extension of a positive trend in health care-- an era of engaged patients looking for personalized health care. Increasingly, patients go see their doctors carrying data from self-tracking tools that record heart rate, blood pressure, diet summaries, miles walked, and so on. For the most part, they are better patients. They pay close attention to how well body and mind are functioning.
In the future, more patients will be bringing health data from DNA tests to their doctor’s appointments. Providers need to keep up with the rapid rise in available genetic information. It is essential, too, that medical schools prepare future doctors to interpret this data so they give good advice on what has been found in a sample of saliva.
Will Dere, M.D., is a professor of internal medicine, executive director of the Program in Personalized Health and associate dean of clinical and translational science at the University of Utah.