How to decipher direct-to-consumer genetic testing

July 25, 2017

DTC genetic testing may provide some relief for patients about their health risks, but more stress for physicians.

For $99 to several hundred dollars, patients can order a range of personalized health information about genetic health risks, without involving a doctor or insurance company. A recent U.S. Food and Drug Administration (FDA) reversal now makes direct to consumer (DTC) genetic testing possible on a larger scale.

In April, the FDA allowed 23andMe, the leader in the DTC genetic testing market, to sell tests for 10 diseases or conditions, providing consumers direct access to certain genetic risk information. This reversal of the FDA’s previous position banning such consumer access paves the way for more companies to market genetic testing to consumers. 

Consumers seek DTC genetic testing for a variety of reasons. “The easiest narrative is that you want to find out you’re at risk for something and hopefully prevent it to improve your health,” says Robert C. Green, MD, MPH, professor of medicine and director of the Genomes2People Research Program at the Broad Institute and Harvard Medical School.

But many patients also seek DTC testing out of curiosity and to explain, not predict, according to a 2017 study in Public Health Genomics, which surveyed 1,648 consumers from two leading genetic testing companies. “A lot of the customers had an illness already and hoped to explain it better to themselves,” says Green, a co-leader of this study. 

In a 2012 Journal of Genetic Counseling survey of 1,048 DTC genetic testing customers, 28% had discussed their results with a healthcare professional.

To date, 23andMe is the only genetics service available that includes genetic health risk reports that meet FDA standards. It has collected more than two million genotyped customers from around the world. But as the DTC genetic testing field becomes more crowded and the price goes down, consumer demand is expected to increase along with the value of the testing due to expected advances in sequencing technology. DTC genetic testing may provide some relief for patients about their health risks, but more stress for physicians.

 

Testing Limitations

DTC genetic tests measure specific markers along the genome. (Consumers can also have their entire genome sequenced-all three billion letters-for $1,000 or more.) The testing process is easy for consumers. They spit into a test tube and mail it to a lab, where technicians purify and extract DNA from the saliva sample. It’s tested for more than 500,000 gene variants. 

 

Consumers view their results online through a secure interface. But interpreting the data and applying it in a clinical setting are far more complex, because the risk for many common diseases, such as heart disease, cancer and diabetes, can involve multiple genes. 

Further complicating matters is that many diseases have lifestyle and environmental components. DTC genetic tests can leave consumers and physicians wondering how to interpret the results-or wondering if they are worthwhile. 

When patients ask about the tests, “I tell them, ‘this is only a small piece of the puzzle,’” says Damon Raskin, MD, an internist in Los Angeles. “Just because you’re predisposed to a condition doesn’t necessarily mean you’re going to have it. And if it’s a condition we can’t prevent, it’s just going to cause a lot of worry, anxiety and sleeplessness.” 

 

Physician Response

Raskin has plenty of company in his response to DTC genetic testing. 

A 2016 study in the Annals of Internal Medicine found that primary care physicians had mixed reactions when patients brought in their own test results. Some physicians took the opportunity to discuss with their patients why they had the tests done. “Other doctors were disparaging or even demeaning toward the patients for having purchased the tests,” says Green, a study coauthor.

“DTC testing doesn’t provide much in the way of medical information that is going to stimulate a doctor to change a patient’s management,” he adds. “But that should change very soon because the DTC genetic testing market is poised to reassert itself.” 

With the FDA’s recent reversal, the tests are likely to become faster, cheaper and more widely used. The results are likely to become more precise, too. “As our interpretation of DTC genetic tests becomes better and better, there’s no doubt in my mind that genomic information is going to become part of everyday medical management,” says Green, who is the principal investigator for the Medseq Project, a study that sequences adult genomes and partners with patients’ primary care physicians to integrate genomic information into patients’ treatment and prevention plans. 

Managing DTC Genetic Testing

When patients ask about DTC genetic testing or come to their primary care visits with their test results, these strategies may help physicians help them. 

 

 

Use DTC genetics tests as a starting point. 

If patients are just considering DTC genetic testing, ask about their motivation and discuss the risks and benefits. In the 2017 Public Health Genomics study, nearly 40% of respondents said they had not considered the possibility of unpleasant information prior to purchasing personal genetic testing services.

“DTC genetics tests can start conversations. That’s where we have a lot of opportunity,” says Erica Ramos, MS, CGS, president-elect of the National Society of Genetic Counselors. Ramos asks patients who come to her with their 23andMe results about what they were looking for in the first place. Then she assesses whether the test results address the patient’s concerns and if there may be a need for additional testing. 

 

Assess clinical validity. 

If patients bring in their DTC genetic test health results, assess whether the test is equivalent to a clinical laboratory test. 23andMe’s carrier test for cystic fibrosis, for example, is approved for clinical use by the FDA. 

To further determine a DTC genetic test’s validity, ensure that the lab is Clinical Laboratory Improvement Amendments (CLIA)-certified with a quick web search on the Centers for Medicare & Medicaid Services (CMS) website (bit.ly/CLIA-lab-lookup). (23andMe uses CLIA-certified labs.) More CLIA-certified labs are starting to offer DTC genetics testing services. 

 

Order clinical testing. 

If a patient’s test results indicate a possible problem -maybe they’re a carrier for cystic fibrosis or have a trait for lactose intolerance-“know where your comfort level begins and ends in interpreting those results,” Ramos says. 

 

If you’re confident in your test interpretation skills, you might choose to order clinical testing to corroborate the patient’s DTC test results or screen those who are at higher risk for disease earlier or more often than typically recommended.

 

Make a referral. 

If you’re not sure how to interpret the significance of a patient’s DTC genetic test, refer him or her to a certified genetic counselor (a professional with specialized training in medical genetics and counseling) or geneticist (a medical doctor or medical researcher who has completed a fellowship or other advanced training in medical genetics), if appropriate, for a more in-depth evaluation. 

Patients can also be referred to companies like Genome Medical, which focuses on translating genetics testing insights into recommended changes for clinical care. (Patients pay $149 to $350 for the service.) 

 

Encourage patients to read the fine print. 

Some DTC genetic testing companies require consumers to sign a release that allows their genetic information to be used for population studies by researchers. Are they comfortable having their genetics available in that manner?

 

Do the homework. 

Medical institutions are starting to teach genetics and genomics to medical professionals in training and residency programs. Established physicians can take advantage of continuing medical education opportunities.

Professional organizations are trying to provide resources to increase practicing physicians’ understanding of the field. The American Society for Human Genetics, for example, is championing continuing education for medical practitioners. Similarly, the American College of Medical Genetics is creating ACTion sheets that describe the immediate actions a health professional should take when communicating with patients and determining the appropriate follow-up steps when confronting adult genetic variations. 

23andme.com and the National Society of Genetic Counselors also have information about genetic testing on their websites that can be helpful for physicians.. Overall, physicians can play an important role in this new era of genomic medicine and add value to their patient consultations by educating themselves. 

“Genetics is like any other specialty. There are going to be specialists with deep domain knowledge,” Green says, “But there are also going to be layers of knowledge that every physician should master and be comfortable with.”