1. From the Department of Internal Medicine, Sections on Cardiology (D.M.H., D.A.M.), Medical Genetics (T.D.H.), and Hematology and Oncology (J.O.), and the Departments of Public Health Sciences (D.M.R.) and Biochemistry (D.B.), Wake Forest University School of Medicine, Winston-Salem, NC; the Department of Epidemiology and Biostatistics (E.V., J.A.S., D.G., S.B.H.), University of California, San Francisco; and the Department of Medicine (V.B.), University of Alabama at Birmingham.