If you mail off a vial of your saliva and wait three to six weeks, you can learn about your risk for a number of genetically influenced health conditions. This is a familiar process to the more than 12 million people who’ve taken the plunge into personal genomics.
The “spit kit” industry has grown considerably since 23andMe launched the first direct-to-consumer genetic testing service roughly a decade ago. Today, there’s a fleet of 23andMe competitors vying to sequence your genome, a process that entails scanning a portion of your genes for mutations associated with specific health issues. Other types of personal genomics companies, such as Promethease, analyze consumers’ genetic data for a wider array of genetic disease markers.
The one thing you’re not supposed to do with your spit kit results is take it them too seriously. At least, that’s what personal genomics companies are legally required to state. DTC genetic testing isn’t nearly as comprehensive as clinical-grade testing, nor is it subject to the same quality-control measures. Given those uncertainties, the FDA makes 23andMe and its ilk tell consumers that their services are intended for recreational, not diagnostic, purposes.
In reality, many people take their DTC tests quite seriously, often assuming they have clinical relevance. In one 2010 study on early adopters of personal genomics, most participants said they expected to receive medical advice from their primary care providers based on their DTC results. Are doctors ready to furnish such advice? In 2012, only 15 percent of respondents in a survey of family medicine practitioners and internists said they felt prepared to answer patients’ DTC genetic-testing questions.
But that was six years ago. We wondered how doctors feel about fielding patients’ 23andMe questions in 2018. Should you bring up your test results at your next checkup? Five doctors sound off:
Department of Family Medicine and Rural Health, Florida State University College of Medicine
MD, MPH, FAAFP
It is absolutely essential that results be discussed with PCPs for several reasons. First of all, these companies are not held to the highest standards of accuracy like certified genetic labs. That means that there are many cases of incorrect results being reported. This includes both false positives (saying you have the genes for a disease when you actually do not) and false negatives (saying you do not have the genes for something, when you actually do). One of the first things that the PCP can do is arrange for testing at a certified genetic testing facility. They might also arrange for genetic counseling to better understand the impact on one’s children.
Additionally, it is important to put the results in context of the rest of your life and lifestyle. We know that having the genes for a condition will increase the chances of that condition, but genes can get turned “on” or “off” by your lifestyle and other factors. Having the gene for Alzheimer’s, for instance, does not make it inevitable. Furthermore, people should not think that just because they do not have the gene for something (say, breast cancer) that they no longer have to worry about it. Their chances may be decreased without the gene, but that does not mean the chances are zero.
Finally, the test should be put into perspective with the rest of each person’s overall health, family history, behaviors, etc. Every doctor can tell you about a patient who gets overly concerned with a slight cholesterol elevation while still smoking cigarettes. Your primary care doc should know you best and can help you to understand the results, put them into perspective and advise you on what to do next.
Assistant professor of internal medicine, Mercer University, Georgia
If a patient has this testing done without discussing it with their PCP first, I think it would be best to share that information with the physician so they could can give guidance on how best to interpret the information and use it in family planning or preparing for potential future medical problems, or for any other reason someone might do this testing.
I really think the best way to handle this kind of testing is to sit down with your primary care doctor [before receiving the results] and discuss why you are interested in the testing, what you hope to accomplish with the testing, how the results could affect you and what you would do in the case something came back positive. For many genetic conditions, it would seem family planning would be the most helpful application. Some people may decide to have children or abstain from doing so based on these results.
Indiana University School of Medicine, Department of Medical and Molecular Genetics
Consumers of DTC genetic testing should involve a healthcare professional in the interpretation of results to better understand the test’s limitations and the potential impact of results.
DTC companies usually do not know the history of the individual having testing, and the interpretation of genetic results therefore are not personalized. Genetic testing should always be interpreted by a trained professional in the context of one’s health and family history. Important details of testing may not be obvious. For example, a “negative” result often does not rule out one’s inherited risk. The test may have looked at only a few of the most common changes in a gene rather than the entire gene, such as with the 23andMe test of the BRCA genes [associated with breast cancer], or the test may have focused on major genes involved in disease risk and not examined other genetic contributors.
Recent studies have also found a high error rate with DTC testing. For these reasons, genetics professionals recommend against DTC genetic testing; when DTC testing does occur, confirming the results in a lab is useful.
What this means for someone who has DTC results in hand is that reaching out to their PCP for help with next steps is important. While PCPs may not have the advanced training needed to navigate testing complexities, they are well-equipped for giving patients an appreciation of these complexities and can aid in identifying a genetics professional that can provide this support.
Assistant professor, Department of Family and Community Medicine, UT Health/McGovern Medical School
Patients should most definitely tell their primary care providers about their test results, for two big reasons.
First, if a patient is carrying a condition that their physician doesn’t know they have, then the physician is already at a disadvantage when it comes to providing good care. It’s common sense. No decent physician would make their patients feel guilty about confiding in them.
Second, there are some specialized tests that really require the assistance of a geneticist or a genetics counselor. Take the BRCA test — whenever we get those kinds of results, we almost always refer patients to someone who [specializes in] genetic testing… so that once the results come back, there’s someone who has a solid foundation in how to handle that information.
Many tests in medicine have sensitivities and specificities associated with them, and can be falsely positive or falsely negative, depending on the markers used. When it comes to DNA testing, the question is more about “what do we do with the information?”
Patients might need a referral to see a genetics specialist; it depends on the insurance. Patients who have [plans] that require pre-authorization [for specialist care] would automatically need them. But it wouldn’t surprise me for [a genetics specialist] to tell a patient to see their PCP first, even if their insurance doesn’t require it.
Associate professor, Department of Community Health Sciences, Boston University School of Public Health
If a patient has undergone testing and receives a result that is concerning to them, then they really should reach out to a genetics professional, such as a genetics counselor. These individuals are trained to assess the results in the context of a patient’s personal and family medical history to determine if further clinical confirmation testing is necessary. Patients should never assume the test results from DTC companies are accurate or complete.
Answers have been condensed and lightly edited.