The genetic mutation found in a small group of people helps protect their heart against the effects of high-fat diet, U.S. researchers reported Thursday.
It may open the door to new therapies for cardiovascular disease.
High blood levels of triglycerides, one of the most common types of fat in our food, have been linked to heart disease.
A team of researchers from three U.S. universities conducted a study on volunteers from the genetically homogeneous Lancaster Amish population, to search for genes that contribute to individual differences in the body's handling of triglycerides.
The researchers used blood samples to look for DNA markers throughout the volunteers' genomes that might be associated with blood triglyceride levels.
This "genome-wide association study" led them to a mutation in the APOC3 gene, which encodes a protein, called apoC-III that inhibits the breakdown of triglycerides.
Individuals with this mutation produced half the normal amount of apoC-III and had the lowest blood triglyceride levels, presumably because they were able to break down more of the fat in their blood.
The same individuals also had high levels of "good" cholesterol and low levels of "bad" one, and their levels of artery-hardening were relatively low, suggesting that they are less likely to develop cardiovascular disease.
If researchers could develop drugs that target apoC-III or the gene that encodes it, these drugs might be useful against heart disease, the authors suggest in their papers published in the journal Science.