[1] Univ Coll London Hosp NHS Fdn Trust, Paediat & Adolescent Endocrinol, London NW1 2PG, England
[2] UCL Great Ormond St Inst Child Hlth, London, England
[3] Univ Coll London Hosp NHS Fdn Trust, Endocrinol, London, England
[4] Univ Coll London Hosp NHS Fdn Trust, Urol & Androl, London, England
[5] Alder Hey Childrens NHS Fdn Trust, Endocrinol, Liverpool, Merseyside, England
[6] Univ Edinburgh, Div Reprod & Dev Sci, MRC Ctr Reprod Hlth, Edinburgh, Midlothian, Scotland
[7] Royal Hosp Sick Children, Dept Endocrinol & Diabet, Edinburgh, Midlothian, Scotland