What Can You Tell Me?
While genetic tests can be used for diagnosis—someone demonstrating features of Down syndrome, for example, might be tested to confirm the presence of an extra copy of chromosome 21—most are performed for predictive purposes. And that has opened up a realm of uncertainty, because many patients—and even some clinicians—do not understand the concept of absolute risk.
The problem has been compounded by the influx of direct-to-consumer (DTC) genetic testing kits. Visit certain Web sites—even the ubiquitous Amazon.com—and you can purchase a kit that provides everything you need to swab the inside of your cheek and send the sample away to a laboratory for analysis. The resultant report will indicate your likelihood of developing certain diseases. (Note: The FDA, among other federal agencies, has questioned the accuracy of some of these kits and whether their marketing claims promise more than they can deliver.) But patients often can't put that information into a proper perspective.
"When I had my DTC genetic testing," Rackover says (he decided he couldn't teach students about it if he didn't experience it for himself), "I received 42 pages of information. And I had to learn to deal with absolute risk. It's basically a communications game of helping people deal with information they don't want to know."
Genetic testing that is ordered, or recommended, by a clinician will have a context to it. The patient will presumably have undergone counseling with a genetics specialist, and/or the primary care provider may have explained to the patient why the testing is beneficial and what information can be gleaned. But when people submit their own samples, they often aren't prepared for the answers they receive.
"The report is going to talk about your potential for the future," Rackover says. "Unless somebody is comfortable with that, when they see all these results—what you might get in your lifetime—for some people, it creates more anxiety than anything."
"When a person sends their cheek swab away, they get information back that they may or may not really understand," McCaffrey says. "If they don't have a primary care provider—an NP, a PA, a physician—to go to for an explanation, they can become very frightened and unnecessarily anxious about the results."
Even when patients bring their results to a primary care provider, that clinician might not be able to offer much enlightenment if he or she is not comfortable with and knowledgeable about genetics. Even to someone with medical or nursing training, the information can be dense and confusing. In fact, today's situation reminds Rackover of the 1970s, when CT scans and MRIs were making their debut.
"I remember this famous neurosurgeon in Philadelphia telling me, 'This machine is coming from England that is going to revolutionize medicine,'" he recalls. "That was the CT scan. Then when that and the MRI first came out, radiologists didn't know what they were looking at. There was too much information. And what we're getting from all the genetic testing is: The high-level stuff is very good information, but we don't know what it relates to yet."