By Matt Jones
NEW YORK (GenomeWeb News) – Genetic tests sold directly to consumers that provide predictions on disease risk have made some personalized medicine watchers wary that these tests could cause unnecessary psychological stress and worry among customers about their risk of disease, but a new study from Mayo Clinic suggests that those worries may be minimal.
After surveying people who provided saliva samples for SNP tests for 12 diseases, as well as a control group, for a year, Mayo found the direct-to-consumer tests had little or no measurable impact on the psychological health or behavior.
"We looked for evidence of increased concern about disease based solely on genetic risk, and then whether the concern resulted in changes in health habits," said co-author Clayton Cowl, a physician in the Mayo Clinic Executive Health Program that provided the study's 150 participants.
Published in the October issue of Mayo Clinic Proceedings, the randomized study found that patients taking the DTC tests did experience "modestly elevated" worries about disease risk one week after the genetic tests were completed. However, after one year patients who had taken the tests were no more stressed than those in the control group.
The study also found that the people who had taken the tests and experienced an increase in worry were likely to be concerned about unfamiliar diseases, such as the thyroid condition Graves' disease, than more common ones like diabetes.
Analysis of the results also showed that men whose genetic risk of prostate cancer was at lower risk than the general population were "significantly less stressed about the disease than the control group," Mayo said.
Mayo said that this is the first clinical trial to use predictive genomic risk assessment in a real-world preventive care setting.
While the study found little evidence that DTC genomic risk tests influenced the perception of risks or patient worry as much as "some scientific critics and commentators" have proposed, Mayo suggested that because patients and doctors are likely to make further screening or preventive decisions soon after receiving genomic results such tests may still be relevant in policy debates.
"Our findings suggest that oversight of emerging genomic technologies should be targeted toward diseases and conditions in which the potential for harm is greatest," the authors wrote.
Because worries and stress about predictive genetic risk information appears to be "neither predictable nor enduring," policymakers should take a nuanced approach to oversight questions and keep an eye on incoming data about the clinical validity and utility of such genomic risk assessments, the authors said.
"The ability to determine the actual utility of these tests, that is, whether a calculation of genetic risk accurately predicts disease, is still several years away," Cowl said.
Genetic Alliance CEO Sharon Terry told GenomeWeb Daily News in an e-mail today that she was "not surprised" by the findings about the participants' lack of distress, pointing out that recent research has shown that people who are given their ApoE4 status, indicating risk for Alzheimer's disease, do not "seem to suffer increased anxiety."
"We also know that people 'forget' even important information about their health status, so I am not surprised any effect weakened over time," she said. "Of course the study is limited, but I think we have seen enough studies that show the same general trend."