Researchers have now discovered that four rare gene mutations can not only lower the levels of triglycerides, a type of body fat in the blood, but also significantly reduce risk of coronary heart disease.
The results add to the growing body of knowledge that it is not low levels of HDL (high-density lipoproteins), the so called "good cholesterol", but high levels of triglycerides in the blood that could lead to coronary heart disease.
The mutations all cripple the same gene, called APOC3, suggesting a powerful strategy in developing new drugs against heart disease, the findings showed.
Coronary artery disease, the most common form of heart disease is a major cause of heart attack and death worldwide.
"The combination of our genetic results, together with recent clinical trials of drugs that raised HDL levels but failed to prevent heart disease, are turning decades of conventional wisdom on its head," said Sekar Kathiresan, director of preventive cardiology at Massachusetts General Hospital in the US.
HDL and triglycerides are both correlated with heart attack, and have an inverse relationship with one another - the lower the HDL, the higher the triglycerides.
"It has long been presumed that low HDL is the causal factor in heart disease, and triglycerides are along for the ride. But our genetic data indicate that the true causal factor may not be HDL after all, but triglycerides," Kathiresan explained.
For the study, researchers sequenced the exomes of nearly 4,000 people, searching for genetic variants associated with blood triglyceride levels.
Individuals carrying a single APOC3 mutation had almost 40 percent lower blood triglyceride levels.
The study appeared in New England Journal of Medicine.
