Earlier this year, consumers were close to being able to pick up a saliva-based genetic test for disease risk the next time they ran to the drug store for aspirin or sunscreen. But even though the tests are still available for purchase online, consumers, geneticists and other groups quickly started to ask questions about the reliability of these off-the-shelf, over-the-counter genetic tests—and whether consumers would be savvy enough to digest results on their own.

In April the U.S. Food and Drug Administration (FDA) raised questions about the tests, and Walgreens elected not to sell them in stores. And in June the agency sent letters to four makers of direct-to-consumer (DTC) medical genetic tests alerting them that they might soon be subject to regulation.

Should consumers be able to send away for their genetic profile that purports to tell them more about the extent to which they might need that aspirin to cut their risk for heart trouble or a stronger SPF to stave off skin cancer? Should only tests with certain health implications, such as cancer risk or drug metabolism estimates, be regulated by the government?

The debate continues, highlighted by two opinion essays published online August 11 in Nature. (Scientific American is part of Nature Publishing Group.) Some argue that health and medical-related tests should be provided only by certified professionals (akin to allowing only licensed radiologists to interpret MRI brain scans). But others assert that tests should be regulated based on the level of risk they pose to the consumer (as medical devices are ranked and evaluated).

The regulatory framework for the FDA's many charges is a tangled one, influenced by consumer and industry lobbies, government funding trends and innovation-driven changes. Some products, such as prescription drugs, are subject to years of rigorous, peer-reviewed research, whereas others, such as cosmetics, are largely left for makers to determine safety and efficacy.

So far, DTC genetic tests have largely fallen into the latter category. But some tests already have proven scientific track records, such as those that look for an established mutation with firm correlations as in the case of cystic fibrosis. "A categorical ban on DTC testing using validated tests would be difficult for the FDA to justify," Gail Javitt, of the Berman Institute of Bioethics at Johns Hopkins University, wrote in her opinion piece.

Because current genetic tests range from firm mutation-disease risk correlation to murkier gradients of probability, Javitt argued that tests should be regulated accordingly. Simple, clear-cut tests could be sold much like pregnancy tests, making them widely available to consumers. Others with more complex analyses or implications should be administered more like counseling-centered HIV tests or more clinically based diagnostic procedures, she noted. And to ensure consumers aren't subjected to overstated—or misstated—promises about test results or accuracy, she recommends the U.S. Federal Trade Commission be involved in keeping an eye on the industry.

Others, however, do not think a stepwise approval program is practical. "If the FDA follows through on the approach that it seems to be pursuing—and regulates the interpretation of genetic tests in impractical detail—at best, a huge amount of government time and money will be wasted," Arthur Beaudet, of the Department of Molecular and Human Genetics at Baylor College of Medicine, wrote in his opinion essay. "At worst, genetic diagnostics will grind to a halt." He echoes others in the field who note that many general genetic test results need interpretation and "a level of expertise that is currently the capacity of even most physicians." The easiest approach, for now, he explained, might instead be for the government to relegate all genetic testing to health care settings, where certified professionals can assess and help interpret results.

Perhaps the one thing that both sides of the debate can agree on, however, is that the data generated by these tests will look very different very soon, and "we will be able to interpret them more accurately in one, five or 10 years from now," Beaudet wrote. Impending regulation, however, could have a large influence on how the industry evolves in the future, Javitt noted: "In such a fast-changing landscape, striking the right balance between protecting the public and promoting innovation is crucial."

But trying to make policies today based on estimated progress in the future can be much like calculating long-term health risks with only sketchily understood genetic correlates.

Image courtesy of iStockphoto/zmeel