MONDAY, April 18, 2011 (HealthDay News) -- Given the option, parents considering personal genetic testing to predict their own risks for common conditions are also likely to have their children tested, a new study suggests.
"The more a parent believes they're going to get good news, the more likely they'll want their kids to be tested," said senior study author Colleen McBride, chief of the social and behavioral research branch of the National Human Genome Research Institute, in Washington, D.C. "But that can backfire. Most of them are not going to get a clear, straight-A report card."
In fact, because the tests measure incremental risks and the diseases screened are so common, a majority of parents would learn their children are at risk for developing potentially serious conditions, McBride said.
Hoping to explore the controversial topic of direct-to-consumer genetic testing -- whose accuracy and benefits are still in question -- researchers evaluated responses from 219 parents enrolled in a large health plan. Participants were offered genetic tests to assess their susceptibility to eight adult-onset diseases, including colon, skin and lung cancer; heart disease; osteoporosis; high blood pressure; high cholesterol; and type 2 diabetes.
Parents were more likely to want their child tested if they believed the child was at risk for a condition, were interested in genes' effects on health, or anticipated relief from learning their children were at decreased risk of disease, researchers said. Mothers were more likely to favor testing than fathers.
The study, part of a larger effort by the National Human Genome Research Institute, is published online April 18 in advance of the May print issue of the journal Pediatrics.
Study participants, whose average age was 35, were asked by telephone about their beliefs about the risks and benefits of predictive gene testing for their children, although no children were actually tested in this research.
The parents most interested in the test for themselves made little distinction between the pros and cons of testing for themselves and their children, the study authors reported, generally favoring the information and believing it could lead to better health maintenance and disease prevention.
But McBride and other genetics experts question how useful such tests really are. Hailed as one of the best inventions of the 21st century -- and widely available to consumers online -- the tests do not always produce consistent results and are easy to misinterpret without professional guidance, experts said.
An undercover study of 15 direct-to-consumer genetic tests by the U.S. Government Accountability Office found "egregious examples of deceptive marketing, in addition to poor or non-existent advice from supposed consultation experts," according to a recent report in The Lancet.
Organizations such as the American Academy of Pediatrics have advised against genetic testing of children for adult-onset diseases when the information has not been shown to reduce deaths or disease complications through interventions begun in childhood.
"The big concern out there is these kids are going to show up at the pediatrician and say, 'Hey doc, what do I do?'" McBride said. "Parents see more perceived benefits than may be true."
Dr. Robert Saul, senior clinical geneticist and training program director at the Greenwood Genetic Center in South Carolina, said one worry is that a family might negatively change its lifestyle -- perhaps exercising less -- if they find out their child is likely not at risk for a certain condition, such as high blood pressure.
"The assumption is the tests are conclusive . . . and nothing could be further from the truth," said Saul, also incoming chair of the American Academy of Pediatrics' Committee on Genetics. "I thought it was an important study because it shows that we -- the medical genetics and pediatric communities -- have a lot of work ahead of us to impart information to parents to make sure genetic tests will be used appropriately and judiciously."
The U.S. National Library of Medicine has more information on genetic testing.