To Test, Or Not To Test, Kids' Genes For Adult Diseases

April 18, 2011

Nancy Shute

Should a high school student building a DNA model also have his genetic code tested for disease risks?

Some parents think testing their kids for genes to see if they're at risk for common health problems like cancer or high cholesterol sounds like a fine idea, according to a survey just published in the journal Pediatrics.

Dozens of direct-to-consumer genetic tests for adults are already being sold on the Internet, so it seems inevitable that parents will start to order up home kits that would purport to predict whether little Sophie faces a future risk of, say, osteoporosis, or diabetes.

And that raises big questions about whether these types of genetic tests are more trouble than they are worth — especially for kids.

By and large, doctors still can't use genes to conclusively predict whether a particular person will develop a specific, common health problem. Cancer and heart disease, for instance, are almost always caused by interactions between a number of genes, a person's lifestyle and the environment.

Now, that's not the case for illnesses like cystic fibrosis, a lung disease caused by a mutation in just one gene. But, as the American College of Medical Genetics points out, many genetic tests marketed to consumers "do not give a definitive answer as to whether an individual will develop a given condition, but provide only a risk or probability of developing a disease."

So even if a genetic test says a child has an increased risk of heart disease in adulthood, the advice the pediatrician would give parents whose child showed a genetic susceptibility for a common illness would be exactly the same advice they give all children now: Eat healthy, exercise, don't smoke, take it easy on the booze when you grow up.

In the Pediatrics survey, researchers asked parents who were already participating in a study about genetic testing of adults what they would think about having their children's genes tested.

The 219 parents polled thought that the benefits of genetic testing for children outweighed the risk, saying that they thought conditions like high cholesterol and diabetes were serious health risks, and that it was very important to know the relationship between genetics and health.

They anticipated being happy if they found out that their child had a reduced risk of disease, but discounted the fact that they might be devastated to discover that a child was genetically disposed to a serious health problem, with no treatment in sight.

"It is important to note that the actual risks, benefits, and utility of genetic testing for common preventable health conditions have not been established for adults or for children," the study authors write.

And that uncertain information comes at a significant cost. Prices for at-home genetic tests range from $295 to $1,200, according to the Federal Trade Commission. The agency's consumer fact sheet says, "A healthy dose of skepticism may be the best prescription."

The Food and Drug Administration is wrestling with how to deal with the tests. As blogger and lawyer Dan Vorhaus noted in a post after a public meeting the subject last month, "The issue, for quite some time now, has not been whether the FDA intends to regulate DTC genetic tests." Rather what will the agency require and when?

In the meantime, you might think it over before signing the kids up for online genetic tests over spring break. Signing them up for soccer camp may provide a greater benefit for their future health. And other than a few blown whistles, soccer isn't subject to regulatory review.