Japanese scientists have identified a key gene involved in heart attacks, based on a study of more than 2,600 patients and 2,500 healthy people. The researchers, who published their results in Nature, found that heart attack patients were more likely to have a particular version of a gene involved in inflammation. Team leader Toshihiro Tanaka, of the Institute of Physical and Chemical Research (RIKEN) in Tokyo, says that blocking the gene's effect could lead to new drugs to prevent heart attacks.
It has long been known that people with a family history of coronary artery disease are at increased risk of having a heart attack, although factors such as diet, diabetes and smoking also play an important role. Coronary artery disease refers to a 'thickening' of the inside wall of the arteries that supply the heart with blood, usually caused by a build-up of cholesterol. If a blood clot arises and becomes trapped in the narrowed artery, then the condition can lead to a heart attack. Previous studies have identified several genetic factors that could increase the risk of this common disease.
In the latest study, the researchers found that a mutation in a gene called LGALS2, which makes a protein called galectin-2, is linked to an increased risk of heart attack. This in turn interacts with another protein, called lymphotoxin-alpha (LTA), which is involved with inflammation. Research suggests that inflammation, the body's response to injury, may play an important role in triggering heart attacks and strokes, since blood clotting forms part of this response.
Tanaka stresses that galectin-2 is not 'the single gene that causes heart attacks, so even people who don't have it could still be at risk'. Stephen Siegel, a US cardiologist, likened inflammation to the trigger of a gun. He explained that while researchers know that pulling the trigger will 'fire a bullet', and cause a heart attack, they don't know exactly how that process occurs. The new study is getting closer to the true cause, he said, like looking at a firing pin on a gun.