[1] Chinese Univ Hong Kong, Dept Paediat, Hong Kong, Peoples R China
[2] Hong Kong Childrens Hosp, Paediat Nephrol Ctr, Kowloon, Hong Kong, Peoples R China
[3] Azienda USL, Maggiore Hosp, Paediat Unit, Bologna, Italy
[4] Ormond St Hosp Children NHS Trust, Dept Paediat Nephrologygre, London, England