DTC testing: time to step in?
As DTC testing becomes more accessible and popular than ever, we ask whether more regulatory work could – and should – be done
The House of Commons Science and Technology Committee has produced a report recommending that direct-to-consumer (DTC) genomic tests should be more tightly regulated.
The report contains several recommendations, including independent assessment of tests before they are sold, set technical standards and a review of advice and support offered to people receiving results.
What are DTC tests?
DTC genetic and genomic tests are those available for purchase directly by members of the public, as opposed to tests ordered by a health professional. They are often marketed for ancestry tracing and are increasingly popular in the wellness industry.
Most commonly these tests use SNP arrays, but as the cost of whole genome sequencing continues to fall, there are likely to be more whole exome and whole genome tests coming to the market.
What are the issues?
Genetic or genomic tests ordered by a healthcare professional are targeted to answer a specific question, formulated with knowledge of the patient’s symptoms and family history. DTC tests take a more scattergun approach – looking at regions of the genome where variation between individuals is common. This makes it easy for them to miss rare variants that could be of clinical significance or flag harmless variants as concerning – read more here.
As a result, the Royal College of General Practitioners and the British Society for Genetic Medicine released guidance for NHS clinicians who are approached by patients about results from DTC tests.
The guidance urges caution, noting that “many DTC results done without clinical indications may be wrong” and that “there are significant NHS costs in confirming (or more often refuting) DTC testing results and these are not warranted unless there are clinical indications for testing”.
Finding solutions
The report contains five main recommendations:
- DTC tests should be assessed by an independent body before they can be sold:
“We suggest that any such external assessment should cover the test‘s clinical performance (the extent to which a test can provide information about diagnosis, treatment, management or prevention of disease that will lead to an improved outcome), as well as its analytical performance (how well a test predicts the presence or absence of a particular gene or genetic change)“. - Technical standards should be established for DTC tests. The standard would act as a mark of quality for consumers but would also signify that the results they return are of high enough quality to be relied upon by the NHS, reducing the need to re-test patients following DTC findings.
- Requirements for advice and support that are offered alongside DTC tests should be reviewed. The predictive power of tests may be unclear to users, and genetic counselling may be appropriate in some cases.
- Restrictions could be placed on the use of genomic testing on children who cannot give informed consent, except in cases where there is a medical reason.
- The UK‘s data protection framework for DTC testing should be reviewed, based on risks and opportunities presented by technological developments and growing numbers of people using these tests.
“At-home genomic testing has opened the door to a wealth of new information about our ancestry, our health and even the likelihood of disease. Done properly, genomic testing offers great potential for individual knowledge and can provide data which can advance medical research,” said Chair of the Science and Technology Committee, Greg Clark.
“However, these technologies can give rise to questions of quality, which are difficult for consumers to assess, and can sometimes pose challenging ethical questions.”
Want to know more? Helpful information about DTC for clinicians is available on our blog.
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