1. Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada (J.D.R., I.E.H., M.D.Y., L.J.G., P.L.-S.).
2. Department of Pediatrics, University of Utah, and Primary Children’s Hospital, Salt Lake City (S.Y.A., S.P.E.).
3. Molecular Cardiology, Istituti Clinici Scientifici Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico and Department of Molecular Medicine, University of Pavia, Italy (A.M., D.K., S.G.P.).
4. European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (A.M., I.T., L.C., A.B., D.K., B.S., C.S., Y.D.W., S.D., A.A.M.W., E.R.B., J.T.-H., J.P.K., F.D., P.J.S., E.S.-B., S.G.P.).
5. Department of Cardiology I (I.T.), University Hospital Muenster, Germany.
6. Northern Ireland Inherited Cardiac Conditions Service, Belfast City Hospital, United Kingdom (A.R.M.).
7. Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Milan, Italy (L.C., C.S., P.J.S.).
8. Department of Medicine and Surgery, University of Milano-Bicocca, Italy (L.C.).
9. Istituto Auxologico Italiano, IRCCS, Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy (L.C.).
10. Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, Canada (A.D.K., T.M.R.).
11. Clinical Cardiovascular Research Center, University of Rochester Medical Center, NY (V.K., W.Z.).
12. Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN (M.B., J.R.G., M.J.A.).
13. Departments of Medicine (M.B.S., N.C., D.M.R.), Vanderbilt University Medical Center, Nashville, TN.
14. Division of Pediatric Cardiology, Department of Pediatrics, University of Louisville, KY (C.L.J.).
15. Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan (T.A., K.S., W.S.).
16. Cardiac Inherited Disease Group New Zealand, Paediatric and Congenital Cardiac Services, Starship Children’s Hospital, Auckland (L.M., J.R.S.).
17. Pediatric Cardiology and Cardiac Arrhythmias Complex Unit, Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Children’s Hospital and Research Institute, Rome, Italy (A.B., F.D.).
18. Children’s Hospital of Eastern Ontario, Department of Pediatrics, University of Ottawa, Canada (S.U., R.M.G.).
19. Division of Cardiology, Department of Pediatrics, University of Michigan Children’s Hospital, University of Michigan, Ann Arbor (B.D.).
20. Children’s Healthcare of Atlanta, Sibley Heart Center Cardiology, GA (P.F., L.M.K.).
21. Department of Epidemiology and Biostatistics (E.V.), University of California San Francisco.
22. Institute for Genetics of Heart Disease (B.S., S.D., E.S.-B.), University Hospital Muenster, Germany.
23. Cardiovascular Genetics Center, Montreal Heart Institute, Université de Montréal, Quebec, Canada (R.T., J., C.-T.).
24. Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Canada (H.J.D.).
25. Division of Cardiology, Queen’s University, Kingston, Ontario, Canada (C.S.S.).
26. Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St. George’s University of London, and St. George’s University Hospitals NHS Foundation Trust, United Kingdom (Y.D.W., E.R.B.).
27. Department of Pediatrics, Division of Pediatric Cardiology, and Department of Cell Biology, Duke University School of Medicine, Durham, NC (A.P.L.).
28. Amsterdam University Medical Centre, location AMC, Heart Center, Department of Clinical and Experimental Cardiology, The Netherlands (G.M.M., A.A.M.W.).
29. The Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Denmark (J.T.-H.).
30. Department of Medicine, Division of Cardiology, Section of Cardiac Electrophysiology M.M.S.), University of California San Francisco.
31. Division of Cardiovascular Medicine, Stanford University School of Medicine, CA (M.V.P.).
32. Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital and UCL Institute of Cardiovascular Science, London, United Kingdom (J.P.K.).
33. Department of Pediatric Cardiology, Cleveland Clinic, OH (P.F.A.).
34. Inherited Cardiac Arrhythmia Program, Boston Children’s Hospital, Harvard Medical School, MA (D.J.A.).
35. Department of Physiology and Department of Medicine, Toronto General Hospital, University of Toronto, Ontario, Canada (M.H.G.).
36. Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan (W.S.).
37. The Heart and Vascular Research Center, Metro-Health Campus, Case Western Reserve University, Cleveland, OH (E.S.K.).
38. Pharmacology (D.M.R.), Vanderbilt University Medical Center, Nashville, TN.
39. Biomedical Informatics (D.M.R.), Vanderbilt University Medical Center, Nashville, TN.