[1] Inst Child Hlth, London Ctr Paediat Endocrinol & Metab, London, England
[2] Great Ormond St Hosp Sick Children, London WC1N 3JH, England
[3] Peninsula Med Sch, Inst Biomed Clin Sci, Exeter, Devon, England
[4] Birmingham Childrens Hosp, Dept Inherited Metabol Disorders, Birmingham, W Midlands, England
[5] Hop Necker Enfants Malad, Paris, France
[6] Royal Manchester Childrens Hosp, Dept Paediat Endocrinol, Manchester M27 1HA, Lancs, England
[7] Alder Hey Childrens Hosp, Manchester, Lancs, England
[8] Bristol Royal Hosp Children, Dept Child Hlth, Bristol, Avon, England