UW researchers identify genetic link to warfarin response
UW researchers have discovered that a person's genetic makeup influences how individuals respond to a common anticoagulant called warfarin.
A retrospective study of records and blood samples from more than 550 patients on long-term warfarin therapy showed that warfarin response is highly dependent on the gene encoding vitamin K epoxide reductase complex 1 (VKORC1). The study appears in the June 2 issue of the New England Journal of Medicine.
Allan Rettie, professor and chair of medicinal chemistry in the School of Pharmacy, and Mark Rieder, research assistant professor in genome sciences, found that gene variations could determine whether patients should receive low-, intermediate- or high-dose warfarin, and may explain differences in dose requirements for patients of different ethnic backgrounds. The researchers found that 90 percent of Asians carry lose-dose versions of the genes, while African Americans are more likely to have high-dose versions.
Used in conjunction with the clinical data that physicians routinely gather, this information could guide selection of the correct dose for patients because VKORC1 alone accounts for a large portion of the dose variability.
Many people take warfarin to prevent blood clotting after a heart attack, stroke or major surgery. However, too much of the drug can cause excessive bleeding. Too little results in no therapeutic benefit.