[1] UCL Inst Child Hlth, Clin & Mol Genet Unit, London WC1N 1EH, England
[2] Univ Coll London Hosp NHS Fdn Trust, Fetal Med Unit, London, England
[3] Univ Lyon 1, Hop Mere Enfant Lyon, Serv Endocinol & Diabet Infantiles, Lyon, France
[4] Erasmus MC Sophia Childrens Hosp, Dept Pediat Urol, NL-3000 CB Rotterdam, Netherlands
[5] Univ Paris 05, Hop Necker Enfants Malades, APHP Paris, F-75015 Paris, France