[1] UNIV PENN,DEPT BIOCHEM & BIOPHYS,PHILADELPHIA,PA 19104
[2] OREGON HLTH SCI UNIV,DEPT MED GENET,PORTLAND,OR 97201
[3] OREGON HLTH SCI UNIV,DEPT PEDIAT,PORTLAND,OR 97201
[4] UNIV OREGON,INST MOLEC BIOL,EUGENE,OR 97403
[5] HOSP UNIV PENN,DEPT NEUROL,PHILADELPHIA,PA 19104