[1] Univ Newcastle Upon Tyne, Sch Clin Med Sci, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England
[2] Univ Newcastle Upon Tyne, Sch Biochem, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England
[3] Univ Newcastle Upon Tyne, Sch Genet, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England
[4] Childrens Hosp Philadelphia, Div Nephrol, Philadelphia, PA 19104 USA
[5] Sydney Childrens Hosp, Dept Med Genet, Randwick, NSW, Australia
[6] Free Univ Brussels, Erasme Hosp, Dept Nephrol, B-1050 Brussels, Belgium