Breakthrough finds 17 new genetic links that raise risk of heart disease

LANDMARK discoveries into genetic links to heart disease could lead to a new era of research and treatment for the condition, scientists believe.

At least 17 previously unknown genetic variants have been identified that increase the risk of narrowed arteries and blood clots - the main cause of heart attacks and strokes.

The findings from three new studies, published in the journal Nature Genetics, double the known genetic causes of heart disease.

Researchers hope they will lead to better ways of identifying those most at risk and to new approaches to treating heart disease by targeting specific genes and molecules.

Previous studies have shown that up to 40 per cent of heart disease cases can be prevented by lifestyle measures such as taking exercise, improving diet and giving up smoking. But about 50 per cent of the risk of heart disease is thought to be due to genetic factors people are born with.

Heart and artery disease is the world's biggest killer, causing about 12 per cent of all deaths worldwide. Coronary heart disease claims more than 90,000 lives each year in the UK. Although the numbers have fallen rapidly since the late 1970s, Britain still has one of the highest death rates in western Europe.

In Scotland, 3.3 per cent of the population is thought to have heart disease, and in 2009-10 there were almost 11,500 heart attacks recorded.

For the latest study, scientists around the world collected data on many thousands of DNA samples to find genetic variants associated with disease in arteries supplying blood to the heart.

For the largest of the new studies, known as CardioGram, scientists pooled information on more than 140,000 people and identified 13 new genetic "loci" - regions of DNA containing genes - linked to the disease.

Only three of the gene regions appeared to involve traditional risk factors such as high cholesterol and blood pressure, diabetes, smoking and obesity.

Five genetic risk factors were pinpointed by a similar study called C4D conducted by the Coronary Artery Disease Genetics Consortium which looked at data from more than 70,000 DNA samples.

The third study, led by researchers in China, focused on more than 7,000 individuals of Han Chinese ancestry and identified one gene variant.

Professor Nilesh Samani, from the University of Leicester, who co-led CardioGram, said: "Understanding how these genes work, which is the next step, will vastly improve our knowledge of how the disease develops, and could ultimately help to develop new treatments."

British colleague Professor Hugh Watkins, from Oxford University, a leading member of the C4D research team, said: "Our research strengthens the argument that lots of genes have a small effect on your heart disease risk, rather than a few genes having a large effect. Knowing about them will be important for directing research to find new treatments."Professor Peter Weissberg, medical director of the British Heart Foundation, said: "As more and more large scale genetic studies are carried out, we are beginning to identify genetic variants that may play a significant, though small, role in the development of heart disease.

"Each new gene identified brings us a small step closer to understanding the biological mechanisms of cardiovascular disease development and potential new treatments."