1. From University Hospital Bern, Bern, Switzerland (T.B.-E., M.G.); Royal Free London NHS Foundation Trust (U.R., F.G.), University College London (U.R.), and Great Ormond Street Hospital, University College London (P.G., S.S.), London, Royal Manchester Children’s Hospital, University of Manchester, Manchester (S.J.), and RK Statistics, Bakewell (R.K.) — all in the United Kingdom; Emma Children’s Hospital–Amsterdam, University Medical Center, Amsterdam (M.B.); the National Institute of Children’s Diseases,...