1. From the Center for Cardiovascular Disease Prevention (A.D.P., N.R., P.M.R.), the Leducq Center for Molecular and Genetic Epidemiology of Cardiovascular Disorders (A.D.P., N.R., P.M.R.), the Divisions of Cardiology (A.D.P., P.M.R.) and Preventive Medicine (A.D.P., P.M.R.), Brigham and Women’s Hospital and Harvard Medical School, Boston, Mass; and the Department of Pathology (N.R.), Children’s Hospital Medical Center and Harvard Medical School, Boston, Mass.