1. University Medical Center Utrecht; Utrecht The Netherlands
2. University College London Medical School; London UK
3. Radboud University Medical Center; Nijmegen The Netherlands
4. University College London and Great Ormond Street Hospital NHS Foundation Trust; London UK
5. Istituto Giannina Gaslini; Genoa Italy
6. University of Brescia and Spedali Civili di Brescia; Brescia Italy
7. Hospital Sant Joan de Déu, University of Barcelona; Barcelona Spain
8. Hospital Valle de Hebron; Barcelona Spain
9. Université Paris-Descartes, Hôpital Necker-Enfants Malades; Paris France
10. Clinica Pediatrica Università di Torino, Day-Hospital Immuno-reumatologia; Turin Italy
11. Ospedale Pediatrico Bambino Gesù; Rome Italy
12. University of Siena; Siena Italy
13. Università degli Studi di Trieste; Trieste Italy
14. Università di Napoli Federico II; Naples Italy
15. University Hospital La Fe; Valencia Spain
16. Women's and Children's Hospital, University of Adelaide; North Adelaide South Australia Australia
17. Ospedale Santa Chiara, Università di Pisa; Pisa Italy
18. Università Cattolica Sacro Cuore; Rome Italy
19. Hospital de Pediatria Juan P. Garrahan; Buenos Aires Argentina
20. University Childrens Hospital Zurich; Zurich Switzerland
21. Istituto Giannina Gaslini and Università degli Studi di Genova; Genoa Italy