1. Department of Human Development and Health, Faculty of Medicine, University of Southampton , Southampton, SO16 6YD , UK
2. Regional Paediatric Endocrinology Service, University Southampton Hospitals NHS Foundation Trust , Southampton, SO16 6YD , UK
3. MRC Epidemiology Unit, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK
4. NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, SO16 6YD, UK
5. Child Growth Foundation, c/o Kinnair Associates Limited , Aston House, Newcastle, NE5 1NB , UK (affiliation at the time of this work)
6. North East Thames Regional Genetic Service, Great Ormond Street Hospital for Children NHS Foundation Trust , London, WC1N 3JH , UK
7. Wessex Regional Genetics Laboratory, Salisbury District Hospital , Salisbury, Wiltshire, SP2 8BJ, UK
8. The Wessex Clinical Genetics Service, University Hospitals Southampton NHS Foundation Trust, Princess Anne Hospital, Coxford Road, Southampton, SO16 5YA, UK