1. From the Division of Pediatric Cardiology (D.T.H., K.A., S.M.) and Division of Molecular Genetics (W.K.C.), Columbia University Medical Center, New York, NY; New England Research Institutes (V.Z., L.A.S.), Watertown, Mass; Department of Pediatrics, University of Texas Southwestern Medical Center (L.M.), Dallas, Tex; Division of Pediatric Cardiology, Medical University of South Carolina (A.M.A.), Charlestown, SC; Department of Cardiology, Children's Hospital Boston (J.C.L., R.M.), Boston, Mass;...