11 October 2010
ByAppeared in BioNews 579
An international consortium has been set up to study the genetic origins of heart attack and coronary artery disease (CAD).
The CARDIoGRAM (Coronary Artery Disease Genome-wide Replication and Meta-analysis) consortium aims to combine and analyse the data from all currently published genome-wide association studies (GWAS) on heart attack and CAD, as well as some unpublished data.
These data cover more than 22,000 patients and 60,000 healthy individuals, meaning CARDIoGRAM is ten times bigger than the largest previous study. The new consortium aims to capitalise on the statistical power gained from combining numerous studies into this large dataset.
Using this approach, the researchers hope to identify the small effects of the large number of genes involved in this condition. All 13 regions of the genome previously identified by the individual GWAS analyses the consortium intends to use in its meta-analysis only explain a small proportion of the heritability of heart disease.
But one of the principal researchers, Professor Heribert Schunkert from the University of Lubeck in Germany, said: 'By pooling all of the published and unpublished data, we hope to make discoveries that might have been overlooked'.
The consortium has already confirmed three genetic variants previously associated with heart attack. For example, an increased risk for heart attack of 29 percent was found for one of the three SNPs (single nucleotide polymorphisms) in an implicated region on chromosome nine. The data showed that a person with two copies of this risk-increasing SNP, one from each parent, would have an increased risk of 58 percent.
Acknowledging the complex nature of heart disease, Professor Schunkert said: 'We have to accept that almost all persons of European ancestry carry multiple small genetic defects that mediate some coronary artery disease risk. The main aim of the consortium is to identify new disease mechanisms to improve risk prevention'.
CAD is a common condition where the arteries supplying blood to the heart can become blocked by plaques. These are fatty deposits that can prevent oxygen from reaching the muscle cells, causing them to die off. This can weaken the heart and increase the risk of heart attacks. CAD is a complex condition that has both genetic and lifestyle components.
The CARDIoGRAM consortium's main aims and objects are set out in an online publication in Circulation: Cardiovascular Genetics.