Department of Pediatrics (S.T.), Kymenlaakso Central Hospital, Kotka and Kuopio University Hospital, 70210 Kuopio, Finland; Departments of Medicine, Physiology, and Human Genetics (G.N.H., L.C.), McGill University, and Experimental Therapeutics and Metabolism, McGill University Hospital Centre-Research Institute, Montreal, Quebec, H3H 2R9 Canada; Children's Hospital (H.V., O.M.), Helsinki University Central Hospital and University of Helsinki, 00100 Helsinki, Finland; Departments of Laboratory Medicine and Pathobiology, Medicine, and Genetics (B.S.P.L., B.Y.L.W., D.E.C.C.), University of Toronto, Toronto, Ontario M5S 2J7, Canada; Division of Endocrinology (M.J.V.), Department of Medicine, Helsinki University Central Hospital, 00029 Helsinki, Finland; Folkhälsan Institute of Genetics (O.M.), 00014 Helsinki, Finland; and Department of Molecular Medicine and Surgery (O.M.), Karolinska Institutet, and Department of Clinical Genetics, Karolinska University Hospital, 17176 Stockholm, Sweden.