Affiliation: | 1. Biochemical Diseases Laboratory, B.C. Children's Hospital, 4480 Oak St., Vancouver, B.C. V6H 3V4, Canada Department of Medical Genetics, University of British Columbia, Vancouver, B.C., Canada;2. Laboratories of the Neurology Service, Massachusetts General Hospital, and the Department of Neurology, Harvard Medical School, Boston, MA, U.S.A.;3. Department of Medical Genetics, University of British Columbia, Vancouver, B.C., Canada;4. Biochemical Diseases Laboratory, B.C. Children's Hospital, 4480 Oak St., Vancouver, B.C. V6H 3V4, Canada |