1. EPSA|ERNICA Registry, European Reference Network for Rare Inherited and Congenital Anomalies, Rotterdam, the Netherlands
2. Dutch Institute for Clinical Auditing, Leiden, the Netherlands
3. Department of Pediatric Surgery, Erasmus Medical Center, Rotterdam, the Netherlands
4. Department of Pediatric Surgery, Hannover Medical School, Hannover, Niedersachsen, Germany
5. Department of Pediatric Surgery, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam & Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
6. Amsterdam Reproduction and Development Research Institute, Amsterdam, the Netherlands
7. Developmental Biology and Cancer Research and Teaching Programme, UCL Great Ormond Street Institute of Child Health, London, United Kingdom of Great Britain and Northern Ireland