[1] Univ Autonoma Madrid, Fdn Jimenez Diaz, Unidad Dialisis, Madrid, Spain
[2] Univ Naples Federico II, Dept Nephrol, Naples, Italy
[3] Genzyme Corp, Cambridge, MA USA
[4] Univ Versailles St Quentin Yvelines, Hop Raymond Poincare, Garches, France
[5] Infermi Hosp, Dept Nephrol & Dialysis, Rimini, Italy
[6] Hosp Sao Joao, Fac Med, Dept Nephrol, Oporto, Portugal
[7] Hosp Sao Joao, Fac Med, Dept Human Genet, Oporto, Portugal
[8] Cent Univ Venezuela, Luis Razetti Sch Med, Dept Physiol, Caracas, Venezuela
[9] Gen Hosp Slovenj Gradec, Dept Internal Med, Slovenj Gradec, Slovenia
[10] Salford Royal NHS Fdn Trust, Salford M6 8HD, Lancs, England
[11] Univ Wurzburg, Div Nephrol, Dept Med, Wurzburg, Germany
[12] Univ Alabama Birmingham, Div Nephrol, Birmingham, AL USA