FDA Panel Says Home Gene Tests Need MD Input

by jeeg 11. March 2011 23:43

Certain types of genetic tests that are available for at-home use without a prescription should not be used without the involvement of a physician or genetic specialist, an FDA advisory panel recommended.

So-called direct-to-consumer (DTC) genetic tests can provide information ranging from a whether a person is lactose intolerant, at risk of developing Alzheimer's disease, or likely to respond to a certain type of drug. After taking a quick blood or saliva sample in the privacy of one's own home, the test is mailed to a laboratory for interpretation and the person is later sent his or her results.

But some of those results -- for example, a person's likelihood of developing heart disease -- are of limited utility without the involvement of a physician, agreed members of the FDA's Molecular and Clinical Genetics Advisory Panel, which wrapped up a two-day meeting on DTC testing on Wednesday afternoon.

"I want any test that has a high predictor that a person will get a disease, I want that filtered through a physician," said panelist Valerie Ng, MD, PhD, a pathologist at the University of San Fransisco in Oakland, Calif.

The panel wasn't clear on whether that would mean a physician would have to order the test, or if a physician would have to interpret the test, or both. That will ultimately be up the FDA to decide. The agency -- which may decide to make certain tests that are currently DTC available by prescription only -- isn't required to follow the advice of its advisory committees, but it often does.

Physician involvement is not nearly as important for nutrogenetic tests that tell a person how their body processes a certain type of food, or for other less-serious genetic information, such as whether the person has thick earwax, the panel decided.

Following the hearing, Alberto Gutierrez, director of the FDA's Office of In Vitro Diagnostics, told reporters that certain types of tests, such as nutrogenetic tests, might be appropriate for at-home use as long as the companies make truthful claims.

Other tests, such as carrier screening tests -- which show whether a person is a genetic carrier of a condition and therefore has a risk of passing it on to their children -- may eventually require doctor involvement.

"We're not going to be able to take one approach to all types of tests," Gutierrez said. "Some may not require a doctor at all and some might require that a qualified health professional be involved, and some might involve the doctor to order the test."

"Most of the committee agrees that physician involvement is necessary," panel chairman John Waterson, MD, PhD, a geneticist at Children's Hospital and Research Center in Oakland, Calif., told MedPage Today after the meeting.

The popularity of DTC tests increased exponentially following the completion of the Human Genome Project. Last year, the FDA informed companies selling the do-it-yourself genetic tests that they weren't in compliance with FDA regulations. That move led pharmacy giant Walgreens to shelve plans to stock a genome mapping kit. Some companies dropped out of the DTC game, and others have been working with the FDA to comply.

Genetic testing companies believe it is an individual's right to have full access to their health information, while others who testified at the meeting felt that having too much medical information can be harmful, particularly if the information is incorrect, or if there's not much a person could do with the information.

Jeremy Gruber, president of the Council for Responsible Genetics, a nonprofit organization founded to stimulate public debate on the social and ethical impacts of genetic technologies, said he thinks the FDA should better regulate DTC genetic testing companies in order to mitigate the harm that could be caused by the tests.

"We believe that everyone should have access to their genome and allowed to sequence it if they choose," said Gruber. However, he added, "We must acknowledge that DTC testing can cause as much harm as good."

Many people argue that knowing genetic predisposition to a certain disease -- particularly one for which there is no treatment, such as Alzheimer's -- adds no value and only serves to increase anxiety.

However, that finding was disputed in a recent study published in the New England Journal of Medicine that found users of the at-home genetic tests did not have increased anxiety after their results were revealed.

"The bottom line from actual studies, is that when people attempt to learn something, they are not upset by what they learn, even when the news is bad," said Mary Pendergast, a lawyer, industry consultant, and former FDA deputy commissioner. "Everyone's lives have trials and tribulations. We can handle it."

>The panelists -- about half of of whom were medical doctors -- also questioned whether average consumers are sophisticated enough to understand their genome screening results, which is part of the reason a physician could be helpful. (However, most physicians aren't trained geneticists, so they can't be expected to be able to accurately interpret the results either, a few committee members pointed out.)

But representatives from the companies that make the tests disagreed with the unsophisticated consumer argument and argued that people deserve to be able to have unfettered access their genetic information.

Pendergast -- who delivered sharply worded testimony during the public hearing that elicited scattered applause from the audience -- accused the panel, and doctors in general, of being "paternalistic."

"The medical profession has objected every time the FDA has tried to give tests directly to consumers," she said, providing home pregnancy tests as an example. "It's, frankly, medical paternalism -- the FDA trying to keep medical products from consumers 'for their own good.'"

The panel also heard from witnesses who referenced a 2010 undercover investigation by the Government Accountability Office (GAO), which revealed that home genetic tests often provide incomplete or misleading information to consumers. For the GAO investigation, investigators purchased 10 tests each from four different direct-to-consumer genetic testing companies -- 23andMe, deCode Genetics, Pathway Genomics, and Navigenics -- and the interpretation of the results differed according to which company analyzed the results.

Emily Walker, MedPage Today

 

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