[1] UNIV CALIF SAN DIEGO,DEPT MED,LA JOLLA,CA 92093
[2] UNIV CALIF SAN DIEGO,DEPT NEUROSCI,LA JOLLA,CA 92093
[3] QUEEN ELIZABETH II MED CTR,MOLEC NEUROGENET LAB,NEDLANDS,WA 6009,AUSTRALIA
[4] MASSACHUSETTS GEN HOSP,DAY LAB NEUROMUSCULAR RES,BOSTON,MA 02129