A survey of European clinical geneticists has revealed opposition to direct-to-consumer (DTC) genetic testing.
 
Of the 131 respondents to the University of Leuven study, 90% reportedly felt that predictive DTC genetic testing should require direct medical supervision (ie. not really be DTC). Smaller majorities also favoured outright prohibition of DTC prenatal gender testing (69%), DTC genome scans (63%) and preconception disease carrier testing (53%).
 
One key concern is that patients do not understand test results and require subsequent expert explanation; 43% of respondents had discussed the results of DTC tests with consumers who subsequently sought their advice. The other worry relating to predictive testing is that the tests are not clinically useful, and may over-estimate risk.
 
This is supported by the findings of a second study led by Professor Cecile Janssens’ research group in Leiden, the Netherlands, which compared risk predictions for eight common diseases from DTC genetic test providers deCODEme and 23andMe, based on simulated data. The researchers found that reported designations of ‘increased risk’ for people with certain genetic variants were based on relatively slight increases above the general population risk.
 
The researchers feel that the DTC tests give a distorted impression of risk based wholly on genetics. Professor Janssens noted that other environmental risk factors such as diet, exercise and smoking typically have a much greater impact on the risk of complex diseases than genetic factors, saying: "We are all aware of the ethical problems surrounding DTC genetic testing, but this study also confirms that their predictions are inaccurate".
 
Comment: Many of these concerns are about communication - how accurately providers explain risk, how well consumers understand it, and what the clinical implications of DTC genetic test results are, if any. There is certainly a need for improvement in this area, and possibly to reduce the direct impact of commercial testing on health service geneticists - but a ban or tighter regulation of such tests is probably not the right way to achieve this.
 
Is it reasonable to ban consumers from accessing services that they may not be able to obtain via health services, such as preconception screening? As previously commented, what about individual autonomy and choice? Also, it should be noted that whilst clinical geneticists have an expert understanding of these issues, they are also inevitably commenting with a degree of bias.
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