DNA test could spot heart attack risk early

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

The test is cheap enough to allow population-wide screening of children, researchers have claimed. Picture: ThinkStock

The Genomic Risk Score (GRS) test is cheap enough to allow population-wide screening of children, researchers have claimed.

Medical and lifestyle interventions can then be employed to reduce the chances of those most at risk of suffering heart attacks in adulthood.

Participants with a GRS in the top 20 per cent were more than four times more likely to develop coronary heart disease than those with scores in the bottom 20 per cent. Many in the “at risk” category lacked the usual heart disease indicators such as high cholesterol and blood pressure.

Senior author Sir Nilesh Samani, from the University of Leicester and medical director of the British Heart Foundation, 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 and avoiding unnecessary screening and treatments for those unlikely to benefit.”

Coronary heart disease (CHD) 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 £9 billion a year.

Doctors use a scoring system under the existing system based on lifestyle and clinical conditions such as cholesterol level, blood pressure and diabetes to identify people at risk of heart disease.

But this method is imprecise, age-dependent and misses a large proportion of individuals who appear “healthy”, but still develop the disease. The scientists mined “big data” from 1.7 million genetic variants in people’s DNA to develop the GRS test.

DNA samples from almost half a million participants in the UK Biobank project aged 40 to 69 were analysed.

The Biobank holds a treasure trove of detailed health and genetic information on around 500,000 people to assist research.

Among the GRS study group were 22,000 people with coronary heart disease.

The GRS test was better at predicting a person’s risk of developing heart disease than each of the classic risk factors alone.

Because DNA sequences are generally fixed from birth, the GRS test can be used at any age.

This raises the possibility of screening children or even infants for future heart disease risk.

The cost of genotyping to calculate a GRS score is less than $US50 (£38). The study was part-funded by the British Heart Foundation.