Scientists already know that variants of certain clotting genes increase the risk of blood clots forming in veins (such as deep vein thrombosis of the legs). However, the involvement of these gene variants in coronary disease has been unclear until now.
John Danesh (University of Cambridge, UK) and colleagues combined data from 191 studies involving a total of about 150,000 participants to investigate seven variants of different clotting genes and the risk of heart disease. They found that a variant of a gene for the plasma protein factor V and a variant of a gene for protein prothrombin were each moderately associated with the risk of coronary disease. Both genetic variants increase the body's production of thrombin, an enzyme that encourages formation of blood clots. By contrast, none of the five other clotting gene variants was correlated with the risk of heart disease.
Professor Danesh states: "These findings could have implications for designing new therapies that target blood clotting pathways to help prevent heart disease. More generally, they suggest that bigger and deeper studies than have been customary will be needed to identify the genetic causes of heart attacks." (Quote by e-mail; does not appear in published paper)