Gene Variation Found to Lower Risk of Heart Disease

Scientists have found strong evidence that a genetic variation affecting immune system cells protects against heart disease. Their findings were reported in the April 15, 2003, issue of the Journal of Clinical Investigation.

The scientists were focusing on a receptor molecule called CX3CR1, which binds with a signaling molecule called fractalkine. Fractalkine, sometimes found in atherosclerotic vessels, attracts immune cells bearing CX3CR1 and helps them attach to infected or diseased cells. A detailed analysis of the offspring cohort of the famous Framingham Heart Study, involving more than 1,800 individuals, showed that a genetic variant of the CXCR1 receptor, called CX3CR1-M280, was associated with a significantly lower risk of heart disease, even after adjusting for all the common risk factors.

A battery of laboratory tests confirmed the suspicion that the human CX3CR1 variant might not function well. The M280 variant did not bind well to fractalkine or respond to its attracting signal, suggesting that people with the M280 variant are less susceptible to arterial inflammation triggered by immune system cells. There has been no evidence so far that the variant causes any ill effects.

"The strength of this study is that it examined an entire population, not just one group of people already at risk for heart disease,” explained Dr. McDermott, of the US National Institute of Allergy and Infectious Diseases (NIAID), who was part of the research team. "When you examine an entire population, you are less likely to overestimate the significance of the risk factor you are studying.”

By establishing a connection between a specific cell receptor and artherosclerosis, the researchers have found a potential target for drugs that could block its action.




Related Links:
US National Institute of Allergy and Infectious Diseases