title: Clinical and genetic study of hereditary spastic paraplegia in Canada.
abstract: OBJECTIVE
  To describe the clinical, genetic, and epidemiologic features of hereditary spastic paraplegia (HSP) in Canada and to determine which clinical, radiologic, and genetic factors determine functional outcomes for patients with HSP.
  
  
  METHODS
  We conducted a multicenter observational study of patients who met clinical criteria for the diagnosis of HSP in the provinces of Alberta, Ontario, and Quebec from 2012 to 2015. Characteristics of the participants were analyzed using descriptive statistics. The main outcome measure for a subset of the cohort (n = 48) was the Spastic Paraplegia Rating Scale. We also used the SPATAX-EUROSPA disability stage (disability score) to assess disability (n = 65).
  
  
  RESULTS
  A total of 526 patients were identified with HSP across the country, and 150 patients had a confirmed genetic diagnosis. Mutations were identified in 15 different genes; the most common wereSPAST(SPG4, 48%),ATL1(SPG3A, 16%),SPG11(8%),SPG7(7%), andKIAA0196(SPG8, 5%). The diagnosis of SPG4 was associated with older age at symptom onset (p= 0.0017). SPG4 and SPG3A were less associated with learning disabilities compared to other subtypes of HSP, and SPG11 was strongly associated with progressive cognitive deficits (odds ratio 87.75, 95% confidence interval 14.04-548.24,p< 0.0001). SPG3A was associated with better functional outcomes compared to other HSP subtypes (p= 0.04) on multivariate analysis. The strongest predictor of significant disability was abnormal brain MRI (p= 0.014).
  
  
  CONCLUSIONS
  The most important predictors of disability in our HSP cohort wereSPG11mutations and abnormal brain MRI. Accurate molecular characterization of well-phenotyped cohorts and international collaboration are essential to establish the natural history of these rare neurodegenerative disorders.
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chrestian
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Dupré
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Ziv
authors.initials: Z
authors.lastname: Gan-Or
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Anna
authors.initials: A
authors.lastname: Szuto
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Shiyi
authors.initials: S
authors.lastname: Chen
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Anil
authors.initials: A
authors.lastname: Venkitachalam
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Jean-Denis
authors.initials: JD
authors.lastname: Brisson
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Jodi
authors.initials: J
authors.lastname: Warman-Chardon
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Sohnee
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Setareh
authors.initials: S
authors.lastname: Ashtiani
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Heather
authors.initials: H
authors.lastname: MacDonald
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Noreen
authors.initials: N
authors.lastname: Mohsin
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Karim
authors.initials: K
authors.lastname: Mourabit-Amari
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Provencher
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Kym M
authors.initials: KM
authors.lastname: Boycott
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Dimitri J
authors.initials: DJ
authors.lastname: Stavropoulos
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Dion
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Ray
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Oksana
authors.initials: O
authors.lastname: Suchowersky
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Guy A
authors.initials: GA
authors.lastname: Rouleau
authors.affiliation: Division of Neurology (N.C., G.Y.), Division of Clinical and Metabolic Genetics (S. Ahmed, H.M., G.Y.), Department of Paediatrics, University of Toronto, The Hospital for Sick Children; Faculty of Medicine (N.C., N.D., J.-D.B., K.M.-A.), Laval University, Quebec City; Department of Neurological Sciences (N.D., P.P.), CHU de Québec; Department of Neurology and Neurosurgery (Z.G.-O., N.M., P.A.D., G.A.R.), McGill University, Montreal Neurological Institute, Quebec; Department of Medical Genetics (A.S.), University of Montreal, CHUM, Quebec; The Hospital for Sick Children Research Institute (S.C.), Child Health Evaluative Sciences/Biostatistics Design & Analysis Unit, Toronto, Ontario; Department of Medicine (A.V., O.S.), Division of Neurology, Department of Medical Genetics (S. Ashtiani, O.S.), University of Alberta, Edmonton; Department of Genetics (J.W.-C., K.M.B.), Children's Hospital of Eastern Ontario, Ottawa; CHU de Québec (K.M.-A.), Hôpital Enfant-Jésus, Quebec City; Department of Paediatric Laboratory Medicine (D.J.S., P.N.R.), The Hospital for Sick Children, Toronto, Ontario; and Department of Molecular Genetics (P.N.R.), The University of Toronto, Canada.
authors.forename: Grace
authors.initials: G
authors.lastname: Yoon