Gene screen for heart disease
A genetic test that can highlight heart attack risk decades before it happens has been unveiled by an international research team.
Heart disease is the leading cause of death in most countries and is linked to smoking, high blood pressure, diabetes, cholesterol levels, family history and a range of lifestyle factors.
But the clinical parameters used to compute an individual's risk of having a heart attack do not take account of genetic influences that will be present from birth and will pre-date the majority of risk factors like diabetes and body weight.
With this in mind, an international team of scientists, including the British Heart Foundation's medical director Nilesh Samani, have developed a genetic risk score mechanism capable of pinpointing people at risk up to twenty years before they develop problems.
The new approach, announced this week in the European Heart Journal, was developed by marrying up the patterns of over 49,000 inherited genetic markers called SNPs - "single nucleotide polymorphisms" - with whether or not more than 15,000 individuals carrying those markers had developed heart disease.
This enabled the researchers to identify a pattern of "risk" markers that together can spell out the likelihood of a person going on to develop heart disease later in life.
The top 20% of men with the most risk markers had a five-fold higher chance of coronary heart disease compared to the 20% of people with the fewest of the markers. And for both men and women, the technique showed that those with the highest genetic risk profile were between 1.7 and 3.2 times more likely to have a heart attack by age 75 compared with individuals with fewest risk markers.
"We need to validate this across other populations to show that it's valid," cautions Samani. "But, introduced to the clinic, this will usher in a paradigm shift."
Specifically, individuals identified on the basis of a genetic risk could be offered disease modifying treatments long before they actually develop any disease.
"We could offer statins from a much earlier age," suggests Samani, although he acknowledges that the study doesn't prove that such interventions would work.
"But we do have evidence that early therapy with these drugs can change the disease course, so it's a reasonable conclusion to draw..."