Acknowledgments
We thank the families for their participation and the clinicians that recruited them. The full list of collaborators is in the Supplemental Note. We are grateful to Margaret Warren-Perry for assistance in recruitment. We are grateful to Sandra Hanks, Silvana Powell, Imran Uddin, and Ann Strydom for technical and administrative support and Tara Mills for assistance with the GWAS analyses. We acknowledge support from the NIHR RM/ICR Biomedical Research Centre and Wessex NIHR clinical research network. K.T.-B. is supported by funding from the Child Growth Foundation (GR01/13). This work was supported by Wellcome Trust Award 100210/Z/12/Z.