[1] WISTAR INST,36TH ST & SPRUCE,PHILADELPHIA,PA 19104
[2] UNIV PENN,DEPT NEUROL,PHILADELPHIA,PA 19104
[3] UNIV PENN,DEPT PEDIAT,PHILADELPHIA,PA 19104
[4] THOMAS JEFFERSON UNIV,DEPT BIOCHEM & MOLEC BIOL,PHILADELPHIA,PA 19107
[5] UNIV HOSP BRITISH COLUMBIA,DEPT MED,DIV NEUROL,VANCOUVER V6T 1W5,BC,CANADA