University of Guelph researchers have determined the location and molecular action of abnormal heart proteins that can cause cardiac failure, a discovery that points to potential new ways to treat the most costly health problem in the world. The study examined gene abnormalities in the actin protein and their role in heart failure. As the most abundant protein in the body, actin helps in vital processes including muscle movement. Abnormal actin genes are linked to heart diseases such as hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). HCM causes excessive thickening of the heart muscle and can lead to sudden cardiac death. In DCM, the heart weakens and enlarges, and cannot pump blood efficiently. Scientists had already linked HCM and DCM to 14 actin gene abnormalities, but this is the first time that many of these variants have been studied at the molecular level.