Thursday, October 11, 2018

Population-wide Genomic Prediction of Health Risks

The UK is ahead of the US in the application of genomics in clinical practice. Part of this is due to their leadership in projects like the UK Biobank (500k genomes with extensive biomedical phenotyping), and part is due to having a single-payer system that can adopt obviously beneficial (and cost-beneficial) practices after some detailed study. Former Prime Minister David Cameron's son has a rare genetic disease, which contributed to his strong support of genomics research in the UK. The decentralized (broken) US health care system, which does not focus on quality of outcome, is having a hard time with no-brainer decisions like making inexpensive genotyping Standard of Care. Will insurance reimburse?

I estimate that within a year or so there will be more than 10 good genomic predictors covering very significant disease risks, ranging from heart disease to diabetes to hypothyroidism to various cancers. These predictors will be able to identify the, e.g., few percent of the population that are outliers in risk -- for example, have 5x or 10x the normal likelihood of getting the disease at some point in their lives. Risk predictions can be made at birth (or before! or in adulthood), and preventative care allocated appropriately. All of these risk scores can be computed using a genotype read from an inexpensive (< $50 per person) array that probes ~1M or so common SNPs.

In technical papers my research group anticipated years ago that even very complex traits would be predictable once a data threshold was crossed. The phenomenon is related to what physicists refer to as a phase transition in algorithm performance. The rapid appearance now of practically useful risk predictors for disease is one anticipated consequence of this phase transition. Medicine in well-functioning health care systems will be transformed over the next 5 years or so.

Test could predict risk of future heart disease for just £40 (Guardian)

Genomic Risk Score test is cheap enough to allow population-wide screening of children, researchers believe

A one-off genetic test costing less than £40 can show if a person is born with a predisposition to heart disease.

The Genomic Risk Score (GRS) test is cheap enough to allow population-wide screening of children, researchers believe. Medical and lifestyle interventions could then be employed to reduce the chances of those most at risk of suffering heart attacks in adulthood.

A study found that participants with a GRS in the top 20% were more than four times more likely to develop coronary heart disease than those with scores in the bottom 20%. Many in the “at risk” category lacked the usual heart disease indicators, such as high cholesterol and blood pressure.

Senior author Sir Nilesh Samani, the professor of cardiology at the University of Leicester and medical director of the British Heart Foundation charity, said: “At the moment, we assess people for their risk of coronary heart disease in their 40s through NHS health checks. But we know this is imprecise and also that coronary heart disease starts much earlier, several decades before symptoms develop.

“Therefore, if we are going to do true prevention, we need to identify those at increased risk much earlier. This study shows that the GRS can now identify such individuals.

“Applying it could provide a most cost-effective way of preventing the enormous burden of coronary heart disease, by helping doctors select patients who would most benefit from interventions.”

Coronary heart disease is the leading cause of death worldwide and claims 66,000 lives each year in the UK. Healthcare costs related to heart and circulatory diseases in the UK are estimated at £9bn per year. ...
Related posts:

Advances in Genomic Prediction

Genomic Prediction of disease risk using polygenic scores (Nature Genetics)

Genomic Prediction: A Hypothetical (Embryo Selection), Part 2

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