1. From the Genetics and Molecular Biology Branch (D.O.), National Human Genome Research Institute, NIH, Bethesda, Md; Laboratory of Molecular Biology (J.M.H.), Cardiovascular Branch, National Heart, Lung, and Blood Institute, NIH, Bethesda, Md; and Laboratory of Cardiac Energetics (A.E.A.), National Heart, Lung, and Blood Institute, NIH, Bethesda, Md.