The Genomic Revolution: An Exciting Opportunity?

Siobhan Harris

Disclosures

May 14, 2019

There's talk of a genomic revolution in the NHS. Health and Social Care Secretary Matt Hancock claims genetic testing will save the NHS time and money.

It's not just testing of seriously ill children and adults with genetic conditions and cancer. The NHS plans to offer a genetic test for anyone, for a fee, in an attempt to predict their risk of developing certain conditions, like coronary artery disease, and Alzheimer's disease. This information will be anonymised and will form part of a huge database.

It's hoped that this bank of genetic information would help build a better understanding of diseases and develop potential life-saving treatments.

The project, which is led by Genomics England is in the development stage.

It raises some important issues, about inherited diseases, ethics, privacy and consent. It also raises concerns about how doctors, nurses, and genetic counsellors are trained to interpret the tests and whether those who have them will be unduly worried about the results.

   

Prof Robert Plomin

Robert Plomin is the author of Blueprint: How DNA Makes Us Who We Are and a professor at the Institute of Psychiatry, Psychology and Neuroscience, King's College London.

Medscape UK asked him what he thought about NHS gene tests and the moves towards genomic medicine in general.

Q&A

What do you think of the idea of the NHS offering genetic testing for healthy people for a fee?

I think in the end it has to happen. Genotyping will become part of the NHS. Some people argue it's too early, but it is very important that we begin to have this discussion now.

There are concerns it'll lead to a two-tier health system. I think at this stage the ultimate volunteers are people who pay for the tests but I predict in 5 or 10 years the tests will be available free to everyone.

Why is it better for the NHS to offer the tests rather than private companies?

Matt Hancock was talking about the NHS test being the whole genome sequencing of all three billion base pairs of DNA. It's said that Genomics England is hoping to get a test done for around £600. If you or I wanted the test through a private direct to consumer company it would costs us a few thousand pounds.

The direct companies provide just a sampling of hundreds of thousands of DNA differences across the genome, but that's nowhere near as good as getting three billion base pairs of DNA because that's the end of the story of genetics. That's all we have inherited.

Are these polygenic scores, to measure pre-disposition to certain conditions and diseases, accurate predictors?

Up until now all these discussions have focused on single gene disorders. There are thousands of them but they are very rare, and even though they are devastating for the people who have them, they don't account for much of the burden of illness in society.

Most of the really burdensome problems are common diseases and conditions like obesity, high blood pressure and cardiovascular disease. These sorts of disorders aren't due to a single gene mutation. What we know from genome wide association studies is that although these things are substantially heritable, it's been very hard to find the specific DNA differences. That's because the effects are very small and there are thousands and thousands of these DNA differences that create the heritability.

If you are trying to predict behaviour or health, we can put these together into a polygenic score and that single number is becoming predictive of some disorders like cardiovascular disease. It's a unique predictor, it doesn't change throughout your life. What you can do is predict risk very early in life. That's important, as modern medicine wants to move towards preventing disorders rather than treating them once they occur.

Is it good for people to know their risk factors, if in reality they can't do anything about changing it?

An easy example is alcoholism; you can prevent it by not drinking so much alcohol. If you knew you were at high genetic risk from alcoholism - even though polygenic scoring isn't that good yet but it's getting better all the time - what would you do? You could cut down on your drinking, monitor your drinking and take breaks from alcohol to see if you are dependent. If you were found to be at a higher genetic risk most people would pay attention to that.

The research is pretty limited as these polygenic scores are so new but why not take advantage of this information? People still smoke and we don't charge them when they come to the NHS with their smoking-related diseases. If people ignore their genetic risk, they'd still be treated anyway.

If someone had a higher risk of cardiovascular disease, they could be given more prognostic testing to see if they are beginning to develop early signs. Something you wouldn't do for everybody as it's too expensive but makes sense if you have a raised genetic risk, with the goal of preventing heart attacks rather than waiting for heart attacks and then trying to treat them.

How could this save the NHS money in the long term? And why is the NHS such a good healthcare system to introduce this?

It can be the salvation of the NHS. I don't know how insurance-based health systems are going to survive the DNA revolution. If you find out you have a high genetic risk for a condition, even though insurance companies aren't supposed to discriminate against you, it may be classed as a pre-existing condition. From a financial point of view why should the health insurance company insure you?  Or if they do, they're likely to charge you a lot more money for insurance. That's the great thing about a universal health system like the NHS. You spread that risk out over the population and you also have organisations like the National Institute for Health and Care Excellence (NICE) that decide what we can and can't afford to pay for. What these polygenic scores and the DNA revolution is showing us is that universal health care isn't some throwback to 1940s idealism. I think it's the future of healthcare.

As far as saving money goes, polygenic scoring and genotyping is relatively cheap to do. You only have to do it once for an individual and you have their genetic risks for everything. We currently create 350 of these polygenic scores from medical problems all the way to psychological traits. Genotyping is cheap and polygenic scores are the best early warning system for problems, as your genome doesn't change in your life.

For example, it's estimated a severe heart attack costs the NHS £700,000 so just preventing a few of those seems like a good thing to do economically – not to mention the personal costs of heart attacks.

And when people talk about the ethics of this do you tell someone they are at risk of a heart attack? I know people divide down the middle but for me forewarned is forearmed. I definitely want to know if I have that risk. Isn't it unethical NOT to let them know? 8% of the UK's population is walking around with a genetically-driven clinical risk of having a heart attack. It doesn't mean they are going to have a heart attack – it just means they are at risk and probably won't know it until the whole syndrome begins to develop when it's harder to reverse it, as opposed to preventing it in the first place.

I do understand that this is a matter of ratio between benefits and risks. It's true these polygenic scores are so new not enough research has yet been done so we don't really know enough. These are complicated issues but I'm a cheerleader for these developments because I am confident that in the end it has to happen. These polygenic scores are beginning to be the best predictors we have and the field is rapidly developing. The genome genie is out of the bottle. It's not a question of whether we embrace these things, it's a question of when.

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