You’ve secured an audience with your overworked GP. You roll into the surgery clearly suffering from the effects of a gargantuan hangover, reeking of fresh cigarette smoke and chomping on a fistful of cheese sticks. After listening to your laboured heartbeat, ascertaining your blood pressure is off the charts and checking how overweight you are, your doctor doesn’t have to be Sherlock Holmes to deduce that, never mind the trifling complaint you presented with, you’re in the danger zone for heart disease, diabetes and God knows what else.
You’ll be sent away with a flea in your ear, told to quit smoking, lay off the booze, chuck out the cheese and develop a taste for quinoa and power-walking. Perhaps you ignore all this excellent advice and die years before your time. No one will be surprised.
But let’s say you bounce into the surgery fresh from yoga class, all bright-eyed and bushy-tailed. You’re a doctor’s dream: a non-smoking, very occasional drinker with a super-healthy diet and a love of the gym. And if a few years hence you’re stricken with some awful disease, everyone will be shocked — you most of all — because no one could have seen that coming.
Or could they? Now, thanks to startling advances in genetics and medicine, there is the possibility that we can see it coming. Lifestyle factors might not be the only game in town when it comes to disease.
Analysis of your genome — the long, complicated and unique genetic recipe that produced you — can highlight specific markers associated with particular diseases; warning flags that have been detected in others. It’s as if, on page 4,323 of this recipe, someone had scribbled in the margin: ‘Heading for a mid-forties heart attack.’Alerted to this, your doctor could perhaps prescribe, say, drugs that prevent the dangerous blockages that can cause heart attacks.
There’s more. Different people respond differently to the same diseases and to the treatments for them but in the past there has been a one-size-fits-all approach. Everyone with disease X has been treated with drug Z. For some patients, it will work. For others, it won’t. In some cases, it might make the patient even more ill.
‘Precision medicine’ (sometimes called ‘personalised medicine’) proposes that within the group ‘patients with disease X’ there are individuals with specific characteristics which reveal their suitability for particular treatments. It allows for tailored treatments depending on an individual’s genetic make-up and other factors.
A definition of precision medicine was put forward in a 2011 report by the US National Research Council: ‘The tailoring of medical treatment to the individual characteristics of each patient.’ It is based, says the report, on the ability ‘to classify individuals into subpopulations that differ in their susceptibility to a particular disease… or their response to a specific treatment… Preventative or therapeutic interventions can then be concentrated on those who will benefit, sparing expense and side effects for those who will not.’ It means medics will be able to predict more accurately which prevention strategies and treatments for a particular condition will work in which groups of people.
This approach will have a profound impact on the prediction, diagnosis and treatment of disease. Sequencing the genome — the cost of which has plummeted from $100 million for the first one to less than $1,000 today — is only part of the story. Professor Dame Anna Dominiczak is Regius Professor of Medicine at the University of Glasgow, a centre of excellence in this newly emerging discipline. ‘Genomics is very important but it doesn’t tell you everything,’ she explains. ‘Sequencing DNA is not the whole of precision medicine. The way we now see precision medicine is that we use all the diagnostic techniques. So, for example, imaging using advanced MRI scanners is a huge part of it. Metabolomics — the study of molecules in cells and tissues — is very important. Old-fashioned clinical assessment is part of it. We want to look at the big picture.
‘When the time comes that everyone’s genome is sequenced — and I think that will happen — it can only tell you about risk. So we can say, this particular type of genetic marker might predispose you to disease X but it doesn’t necessarily mean that you’re definitely going to get it. But maybe those markers dictate preventive measures that can be taken; better diet, stopping drinking, never starting to smoke and so on.’
Dominiczak believes precision medicine will mean a revolution in healthcare, and there are benefits beyond our wellbeing. ‘Precision medicine will save huge amounts of money,’ she says. ‘For example, the current NHS drugs bills is enormous. Some drugs prescribed are ineffective — they might not cause any harm, but if they don’t work, then that’s a huge waste. By doing molecular tests to help identify whether a drug will work or not on particular patients, you could save billions.
‘Also, one of the holy grails is to avoid prescribing drugs that would cause side effects. Sometimes these side effects are drastic and lead to hospital admissions.’
Precision medicine could also boost economic growth by attracting inward investment from industry partners. ‘Some of the work going on in Glasgow has attracted companies from the US and Germany to relocate there,’ says Dominiczak.
Thanks in part to government initiatives from both Westminster and Edinburgh, Britain is currently a world leader in the field. The 100,000 Genomes project announced by David Cameron in 2012, to sequence the genomes of 100,000 NHS patients, reached its target in December, providing a rich database for researchers to mine. Last autumn, scientists at the Universities of Cambridge and Leicester announced that their ‘Genomic Risk Score’ test to identify people at greater risk of heart attacks was more accurate than any other method of predicting heart disease. In theory, children could be tested. It costs around £40.
The work in Glasgow, which was highlighted in the Department for Business, Energy and Industrial Strategy’s Science and Innovation audit, published last month, is being backed by First Minister Nicola Sturgeon’s administration. Sturgeon has described the city’s Queen Elizabeth University Hospital, where this pioneering research and development is taking place, as a ‘world-leading beacon of science and innovation’.
‘The issue now is staying in front, because we’re seeing huge investment in countries such as China and the US and in small countries such as Estonia,’ says Dominiczak. ‘We need to keep running if we want to maintain our lead because others are joining the race.’