1. Department of Pediatric Endocrinology (O.R.-C.), Hospital Infantil Universitario Niño Jesús, Instituto de Investigación Sanitaria La Princesa, 28007 Madrid, Spain;
2. Department of Pediatrics (J.L.G.), Complejo Hospitalario Torrecárdenas, 04009 Almería, Spain;
3. Department of Pediatrics (A.G.), University of Concepcion, School of Medicine, 4070038 Concepción, Chile;
4. Institute for Biomedical and Clinical Science (A.T.H.), University of Exeter Medical School, Exeter EX2 5DW, United Kingdom;
5. Institute of Maternal and Child Research (E.C.), School of Medicine, University of Chile, 8360160 Santiago, Chile