Two huge international studies have identified 17 new genetic variants that are linked to an increased risk of coronary heart disease. The findings more than double the previous known genetic links to heart disease, as published in Nature Genetics this week.
A genetic variant is a piece of DNA that varies from person to person. A variant of a gene changes its expression, which may or may not result in obvious differences among people.
The studies were conducted by Coronary Artery Disease (C4D) Genetics Consortium and the CARDIoGRAM consortium. Funding for the two studies came from the European Union as well as a number of research organisations including the British Heart Foundation (BHF), the Wellcome Trust, the Medical Research Council, and the National Institute for Health Research.
Researchers from both studies compared the entire genomes of tens of thousands of people with and without coronary heart disease to identify the different variations in DNA more likely to be found in people with coronary heart disease.
Research by the C4D Consortium looked at the DNA of more than 15,000 people who had developed coronary heart disease before the age of 60. Professor Hugh Watkins from the Department of Cardiovascular Medicine, at the University of Oxford, was one of the C4D co-leaders of the study. Professor Watkins and his colleagues found five genetic variants that increased the risk of coronary heart disease. This included two that were linked to atherosclerosis, where the buildup of fatty deposits along the walls of arteries causes them to thicken and harden, which can cause heart attacks and strokes. These findings now allow for a greater understanding of the biological pathway for atherosclerosis.
The research strengthens the argument that lots of genes have a small effect on your heart rather than a few genes having a large effect. The CARDIoGRAM consortium, which involved 67 clinicians and scientists from around the world, looked at the DNA of more than 140,000 people, including over 50,000 people with coronary heart disease.
Data was collected from 14 genome-wide association studies of coronary heart disease, and it was confirmed that 10 previously known variants and 13 new variants were linked to coronary heart disease. From the 13 new variants, 5 appear to have showed strong links with other human disease and traits.
Following the two studies, the two consortia will look to work together, and by their combined findings could enable them to reveal further links to heart disease.
