GPs urge caution over DTC genetic testing
Author: Louise Prime
The results of direct-to-consumer (DTC) genetic tests could cause patients undue worry or inappropriate reassurance and increase workload for GP teams, warned* researchers and GP leaders this morning. The Royal College of GPs said GPs simply don’t have the expertise to interpret test results in a sophisticated enough way to be useful to patients, and has called for the companies that market the tests to take responsibility for interpreting the results rather than advising patients to talk to their GP.
In The BMJ this morning, geneticists and ethicists pointed out that some DTC genetic tests, sold online as well as in shops, promise insights into ancestry or disease risks, and others claim to provide information on personality, athletic ability, and child talent; and in some advertising, the tests “were presented as potentially empowering, with the decision to take them portrayed as responsible – a way that people can take an active role in managing their own health”.
But the researchers pointed out that interpretation of genetic data is complex and context dependent – DTC genetic tests might produce unnecessarily worrying false-positive or dangerously reassuring false-negative results. They said people often access the tests without prior discussion with a health professional, but anyone worried about their DTC genetic test results will often then ask their GP or other primary healthcare provider for advice. They advised GPs consulted in this situation:
- Don’t use DTC genetic test results to inform health decisions without further scrutiny. For example, if they found ‘disease-causing’ or ‘likely disease-causing’ variants in genes associated with conditions for which early detection might be possible and/or treatment is available (such as BRCA1, BRCA2,MLH1), inform the patient that further testing often shows that DTC genetic test results are inaccurate, so they might need a blood test to confirm or refute their result, and they might not be offered a genetics appointment.
- Refer anyone with a medical or family history where you would otherwise offer a genetics referral regardless of ‘reassuring’ results from a DTC genetic test.
- If someone who has taken a DTC genetic test presents with symptoms that they are concerned about (or that they think are explained by the DTC genetic result), assess and investigate the symptoms in the same way that you would for any other patient.
- It might be useful to discuss possible sources of error in DTC genetic tests; and shifting the conversation from discussing genetic risk to addressing modifiable lifestyle factors can be an important part of the consultation.
They said DTC genetic testing raises wider questions too: how can we raise public awareness that many genetic results are not clear cut, and might not substantially shift a person’s pre-existing risk of disease? How can we ensure that patients with personal or family histories suggesting a genetic condition are not falsely reassured by DTC genetic test results? And how should additional healthcare costs arising from DTC genetic tests be funded? What regulation might be helpful?
The RCGP said the paper backs up its own concerns over DTC genetic testing. College chair Professor Helen Stokes-Lampard said: “Genomic sequencing data has huge potential to improve the care patients receive in the future – but we agree with the authors of this paper that at present, caution should certainly be advised by both healthcare professionals and the public.
“The College has already voiced concerns about the increasing availability of commercial genetic tests – firstly, because the results could cause undue worry or inappropriate reassurance for patients, and secondly because of the workload implications in general practice.
“Genetic testing shouldn’t simply be done to satisfy a patient’s curiosity about their health as the results could have very real implications. But as it stands, we don’t have the expertise to interpret them in a sophisticated enough way to be of great benefit for our patients.”
She added: “Our members have reported patients coming to see them with the results of commercial genetic tests, asking for them to be interpreted – and some commercial companies actually advise this instead of providing the necessary advice and feedback themselves. But GPs and our teams are already working under intense resource and workforce pressures – with patients waiting too long for a routine appointment as a result – so this is not a good use of our time or NHS resources, and should be the direct responsibility of the companies that are being paid to perform the tests.”
*Horton R, Crawford G, Freeman L, et al. Direct-to-consumer genetic testing. BMJ 2019; 367 :l5688