1. Division of Cardiology, Johns Hopkins Medical Institute, Baltimore, MD (R.T.C., A.G., C.P., C.T., B.M., A.H., S.L.Z., H.T., H.C., C.A.J., K.C.W.).
2. Division of Cardiology, Department of Heart & Lungs (A.G., A.S.J.M.t.R., L.B., S.A.M.), University Medical Center Utrecht, the Netherlands.
3. Member of the European Network for Rare, Low Prevalence and Complex Diseases of the Heart: ERN GUARD-Heart‚ Academic Medical Center‚ Amsterdam‚ the Netherlands (A.S.J.M.t.R., S.-C.Y.).
4. Erasmus MC, University Medical Center Rotterdam, the Netherlands (S.C.Y., A.W., P.v.T.)
5. Department of Cardiology, University Medical Center Groningen, University of Groningen, the Netherlands (M.P.v.d.B.)
6. Amsterdam University Medical Center, Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, the Netherlands (A.W.)
7. Heart Center Leiden, Leiden University, the Netherlands (K.Z.)
8. Montreal Heart Institute, University of Montreal, QC, Canada (J.C.-T.).
9. Department of Clinical Genetics (P.v.T.), University Medical Center Utrecht, the Netherlands.