[1] UNIV HOSP AMSTERDAM,DEPT PEDIAT,1105 AZ AMSTERDAM,NETHERLANDS
[2] STATE UNIV UTRECHT,BIOCHEM LAB,UTRECHT,NETHERLANDS
[3] UNIV MUNICH,KINDER POLIKLIN,D-8000 MUNICH 2,FED REP GER
[4] UNIV MUNICH,INST PATHOL,D-8000 MUNICH 2,FED REP GER
[5] UNIV AMSTERDAM,BIOCHEM LAB,AMSTERDAM,NETHERLANDS