Scientists have pinpointed a gene which seems to play a crucial role in heart attacks.
A tiny mutation may be the key
They found that a particular mutation of the gene occurs more frequently in people who have had a heart attack.
It is thought the gene controls inflammation in the arteries supplying blood to the heart. A blockage here can trigger a heart attack.
The research, by Toyko's Institute of Physical and Chemical Research, is published in Nature.
The Japanese team hopes its work will prove to be a crucial step towards a better understanding of the underlying causes of heart attacks.
The scientists found that the key mutation is caused by just one tiny change to the chemical components of DNA.
Their work is based on an analysis of DNA samples from more than 2,600 heart attack patients.
These were compared with samples from 2,500 volunteers from the general
The heart attack patients were significantly more likely to carry a specific mutation in a gene that produces a protein called galectin-2.
Galectin-2 is known to bind to a molecule that assists inflammation - lymphtoxin-alpha (LTA) - and which is released when a coronary artery ruptures.
The gene mutation appears to change galectin-2, and in turn to affect the amount of LTA that is secreted - possibly boosting inflammation and increasing the risk
of a heart attack.
Professor Jeremy Pearson, of the British Heart Foundation, said: "Over the last decade or so, scientists have realised that the fatty deposits (atherosclerosis) which accumulate in blood vessels are in fact due to a chronic inflammatory disease.
"The current paper strengthens this view, with the novel implication that genes which can control the release of inflammatory proteins from cells may also be related to heart disease risk."
Heart disease is the biggest killer in the western world, claiming 110,000
lives each year in England alone.
A total of 275,000 people in England suffer a heart attack each year.