Their findings may lead to new treatments for patients at risk from blood clots, including those who have had heart attacks, have coronary artery disease, irregular heart beats, or have had heart valve replacement therapy.
The scientists from the MRC's Clinical Sciences Centre at Imperial College in London, and research institutions in Germany, identified the gene that controls the production of a protein essential for the action of vitamin K, which is necessary for the formation of a clot. Their findings are reported in today's issue of Nature (doi:10.1038/427493a).
The drug Warfarin is currently the best treatment for patients at risk from blood clots. Although scientists know it inhibits the action of vitamin K by targeting the protein, thinning the blood and preventing the formation of life threatening blood clots, they do not understand how this happens.
Pinpointing the gene will help scientists understand the link between the protein and vitamin K.
The research team studied the genes of warfarin-resistant rats and patients, and compared them with the genes of families with an inherited disorder in handling vitamin K which prevents them from forming clots properly. A mutation was found in the same gene in all three groups. This mutation identified the gene which, under normal genetic circumstances, controls the production of the protein responsible for the action of vitamin K.
Professor Ted Tuddenham, of the MRC Clinical Sciences Centre, said: "This is an exciting discovery. Patients are treated with warfarin because we knew it prevented the action of vitamin K and therefore the formation of life threatening blood clots. However, we haven't been able to explain how this takes place."
"Pinpointing the target of Warfarin will help us find out more about how vitamin K works. And this may lead to the development of more effective blood thinning treatments for all those whose health is at risk from the formation of blood clots," he added.
Low dietary vitamin K intake has also been associated with an increased risk of bone fractures. One of the most common forms of the fat-soluble vitamin is phylloquinone, which is found in some oils, especially soybean oil, and in dark-green vegetables such as spinach and broccoli.