1. From the Division of Translational Medicine and Human Genetics, Department of Medicine (S.T.N., R.C.B., D.J.R.), Penn Cardiovascular Institute, Department of Medicine (H.Z., M.P.R., D.J.R.), Department of Genetics (N.J.H., D.J.R.), and Department of Biostatistics and Epidemiology (D.S.), Perelman School of Medicine, University of Pennsylvania, Philadelphia.