1. Department of Pediatrics, Ospedale Regionale di Bellinzona e Valli, Bellinzona, Switzerland
2. Department of Pediatrics, University Children's Hospital of Bern, and University of Bern, Bern, Switzerland
3. Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico and Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy