Physicians, Consumers Need Better Understanding of Genetic Testing

Jacquelyn K. Beals, PhD

November 12, 2010

November 12, 2010 (Washington, DC) — The clinical value of current genetic testing would be enhanced by greater oversight and improved physician experience and understanding of the tests, according to participants at a press briefing here at the American Society of Human Genetics (ASHG) 60th Annual Meeting.

In one study discussed at the briefing, a quarter of the patients reported that their doctors didn't understand the results of their genetic tests or know what to do with them. "There is evidence that many physicians are quite stymied by genetics results and really don't know how to incorporate genetic information into their approach," said Barbara A. Bernhardt, MS, CGC, clinical professor of medicine and codirector of the Penn Center for the Integration of Genetic Health Care Technologies, Hospital of the University of Pennsylvania, Philadelphia. "We recognize that we have a long way to go in terms of educating physicians."

There are several issues surrounding direct-to-consumer (DTC) genetic testing: How accurate are the results? How much can consumers trust what they get back from the testing companies? How much clinical validity do the results have? How well do the testing results predict actual risk for disease?

"One of the scenarios that we all wish to avoid is one in which the consumers don't fully understand the results, their physicians equally don't understand the results, and the scientists who generated the results are still arguing about what they actually mean," noted Lynn B. Jorde, PhD, professor and chair, Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, president-elect of ASHG, and moderator of the briefing.

Even among genetic counselors and professionals, there is confusion about how genetic tests are regulated, who provides the oversight, and how a genetic test moves from research to being used for clinical testing.

"There are actually 2 types of tests that are offered in a DTC format. There are tests that we would use every day in genetics clinics that, for many reasons, may be offered in a [DTC] fashion. Then there are tests that haven't moved to the clinic yet," said participant W. Andrew Faucett, MS, CGC, from the Department of Human Genetics, and director of the Genomics and Public Health Program, Emory University School of Medicine, Atlanta, Georgia.

"We're not quite sure of those tests yet; they're not being used for clinical medicine. Sometimes in the discussion, those 2 get blended and mixed a bit. I think it's important to separate them," said Mr. Faucett.

To make things more complex, a laboratory director in the United States can decide when a test is ready to be offered. No government body or other supervisory agency decides when a test has enough supporting evidence to enter the market.

"In our review of the literature, it does appear that most of the [genetic testing] labs are doing a pretty good job with the actual analysis of the tests. We haven't really been able to find any evidence of concern about that," said Mr. Faucett. But, "are they providing usable information? Is this something that will actually [affect] healthcare?" Mr. Faucett asked.

"Most people don't realize that there's no one actually saying that this test is ready or not ready," said Mr. Faucett. "As a result, for healthcare providers and for consumers of DTC testing, it's very important to think about things like analytical validity, clinical validity, and clinical utility . . .  to make sure that the tests they're considering will provide important information, and that it's at a reasonable cost."

Consumers and physicians are also advised to check whether the testing laboratory is certified. Labs in the United States must be certified through Clinical Laboratory Improvement Amendments (CLIA) to return information; however, some laboratories indicate that they follow additional professional guidelines, such as those of the College of American Pathologists, the American College of Medical Genetics, and the Clinical and Laboratory Standards Institute.

Although healthcare providers evaluate other tests on a daily basis, many are not experienced with genetic tests, and often don't know what questions to ask or how to begin evaluating them. Genetic tests can't test everything, Mr. Faucett pointed out. Some look at the full gene, some look only at exons (the DNA transcribed into the mature RNA molecule) or only a certain set of mutations. Physicians and their patients need to ask what a test analyzes, what that information tells them, and whether the information will be useful.

Another consideration is whether the tests have been used in a population the patient is part of. "Most of these studies have been done in upper-middle-class Caucasians," said Mr. Faucett. "So if you don't fit in that group, is the information really relevant and does it apply?"

"Many of these tests have only been [used] in 1 or 2 studies, so you have to take that with a grain of salt. The concept that 23andMe [a DTC test company] uses is interesting. They have a star system by their tests. Some tests, for which they think there's a lot of evidence, have 4 or 5 stars, and some tests only have 1 star," Mr. Faucett explained. "That's something that might be useful to the public when we think about other genetic tests."

National agencies have recently stepped in to provide closer scrutiny of genetic testing. The Centers for Disease Control and Prevention (CDC) published guidelines for molecular testing last year (MMWR Recomm Rep. 2009;58[RR-6]:1-37); the US Food and Drug Administration is considering a review of laboratory-developed tests; and the National Institutes of Health is developing a genetic testing registry.

However, it is important not to overregulate: "I've spent the last 5 years doing a lot of work on rare disease genetic testing," said Mr. Faucett. "If the burden [on the testing labs] becomes too much, some of those tests might not become available. We have to strike a balance of what we need to do to protect the public and to make sure they have appropriate information."

Asked by Medscape Medical News about continuing medical education opportunities in the area of interpreting genetic test results, Mr. Faucett said a lot of programs exist. "I think there is material out there. There's a fair amount of material on the CDC Web site as a result of [Morbidity and Mortality Weekly Report]," he said. "I think the difficulty is getting physicians to use the material. One of the things we found sometimes is that patients going in and asking questions can be a very good motivator! The difficulty is going to be to get that educational opportunity to fit into a busy clinician's schedule."

Ms. Bernhardt and Dr. Jorde have disclosed no relevant financial relationships. Mr. Faucett reports receiving consulting fees or other remuneration from DNA Direct, MEDCO, and PTC Therapeutics.

American Society of Human Genetics (ASHG) 60th Annual Meeting: Press briefing, held November 5, 2010; Abstract 392, presented November 5, 2010; Session 74, presented November 6, 2010.


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