GP patients will have their entire genetic code screened for faulty genes that increase the risk of cancer and heart disease in a new study.
Researchers want to assess the potential benefits of whole-genome sequencing in a healthy population, and how acceptable this screening is to the public.
For the first time, the study will aim to establish whether screening for gene faults that increase the risk of disease can help doctors diagnose cancer, heart disease and other illnesses earlier.
Experts will initially monitor 20 patients for the psychological effects of screening, before expanding to 1,000 GP patients in London, and multiple NHS trusts at a later stage.
If successful, it could pave the way towards much more routine genetic testing to predict and manage patients’ future health in the NHS.
The initiative, called the 90S study, comes amid a rise in popularity of over-the-counter genetic tests, which experts have warned are unreliable and can give falsely reassuring and worrying results.
It is led by Professor Ros Eeles, an expert at the Institute of Cancer Research (ICR), London, and The Royal Marsden NHS Foundation Trust, and Dr Michael Sandberg, a GP at 90 Sloane Street – a private practice from which patient volunteers will be recruited.
They said the initiative “differs fundamentally” from these direct-to-consumer tests because patients will receive the screening in the context of a detailed medical review.
An echocardiogram – a heart ultrasound – will also provide extra data to reassure those with some genetic risk of heart disease but no signs that this is affecting their health.
They will also use blood tests, which they say will reduce the occasional failure of using saliva, while consultant geneticists will discuss any abnormal results.
Prof Eeles told the PA news agency that the over-the-counter tests will give a general pattern, like looking up at the Milky Way in the sky, while their screening is like a “scribe writing your whole genome from beginning to end”.
She said: “We have been very clear we will not feed back results for which we cannot give clear guidelines of how you would alter a patient’s management.
“That’s very, very important – we want medicine that’s going to help patients, not find things that might increase their worry and for which we really don’t have any management at the moment.”
She added: “What we hope is that genetic screening is practical as a way of picking up genes associated with cancer and heart disease, is psychologically acceptable to patients, and can alter the way they are managed by their GP.
“The project will give us crucial information about whether genetic screening in primary care could be feasible, and how we should go about seeking to implement it within the NHS.”
Much progress has been made in identifying inherited causes of disease, such as the BRCA gene faults which increase the risk of breast and ovarian cancer.
The researchers will report on 600 genetic changes known to be linked with disease, or which can have an effect on the way patients respond to specific medicines.
They are looking only for “actionable gene alterations”, which will enable patients to make choices including lifestyle improvements, having specific screenings and receiving targeted treatments.
Half the volunteers will be people with a family history of cancer or heart disease so that the researchers can assess how frequently genetic alterations are picked up compared with people without a family history.
It comes as separate research found that a person’s risk of cancer is affected by genetic variations in parts of DNA previously dismissed as “junk DNA”.
A team of international scientists found that inherited cancer risk is not only affected by mutations in key cancer genes, but also by variations in the DNA that regulate the expression of these genes.
In the future, understanding how this non-coding DNA affects the development of cancer could improve genetic screening, lead to new prevention strategies and help doctors diagnose earlier, they said.
Dr Emily Farthing, senior research information manager at Cancer Research UK, said: “While minor genetic changes only have a small impact on cancer risk, the variations analysed in this study are numerous and common in the population.
“This could begin to explain some of the variation in cancer incidence between individuals and families that cannot be explained through well-known cancer risk genes or lifestyle factors alone.”
The research is published in the British Journal of Cancer.