Genetic flaw that may put some people at far greater risk of heart attacks

May 6 2004

Scientists in Japan have discovered a genetic flaw that may put some people at far greater risk of heart attacks.

The genetic variation that encodes for a protein called galectin-2 may increse the likelihood of myocardial infarction, their study, published yesterday in the British weekly journal Nature, said.

Myocardial infarction is a heart attack that occurs when an artery feeding the heart becomes blocked (occluded) by a blood clot (thrombus) or atherosclerotic plaque such that blood flow is restricted to the heart muscle depriving it of oxygen (ischemia) resulting in death of myocardial tissue, a potentially life-threatening condition.

One of the significant players in this event is the molecule cytokine lymphotoxin-alpha (LTA), which helps to regulate inflammation, a result of the emergency call upon the body's immune system.

Scientists led by Toshihiro Tanaka at the Institute of Physical and Chemical Research in Tokyo found that levels of LTA are determined by the lectin protein galectin-2. In turn, levels of galectin-2 depended on variations in a gene, LGALS2, which controls this protein.

In lab tests, they found that one of three variations they studied could reduce galectin-2 by 50 percent, a fall that they hypothesise is bound to have an effect on secretions of LTA.

Around 4 per cent of Japanese people, they believe, have this specific variant, which is just a single letter in the genetic code.

The researchers cautioned that their theory has yet to be tested on the situation in the human body.