Fruit fly muscles with a hypertrophic cardiomyopathy mutation don't relax properly

(Johns Hopkins Medicine) Using fruit flies, Johns Hopkins researchers have figured out why a particular inherited human heart condition that is almost always due to genetic mutations causes the heart to enlarge, thicken and fail. They found that one such mutation interferes with heart muscle's ability to relax after contracting, and prevents the heart from fully filling with blood and pumping it out.