title: GLUT1 deficiency syndrome: an update.
abstract: BACKGROUND
  Glucose transporter type 1 deficiency syndrome is caused by heterozygous, mostly de novo, mutations in the SLC2A1 gene encoding the glucose transporter GLUT1. Mutations in this gene limit brain glucose availability and lead to cerebral energy deficiency.
  
  
  BACKGROUND
  The phenotype is characterized by the variable association of mental retardation, acquired microcephaly, complex motor disorders, and paroxysmal manifestations including seizures and non-epileptic paroxysmal episodes. Clinical severity varies from mild motor dysfunction to severe neurological disability. In patients with mild phenotypes, paroxysmal manifestations may be the sole manifestations of the disease. In particular, the diagnosis should be considered in patients with paroxysmal exercise-induced dyskinesia or with early-onset generalized epilepsy. Low CSF level of glucose, relative to blood level, is the best biochemical clue to the diagnosis although not constantly found. Molecular analysis of the SLC2A1 gene confirms the diagnosis. Ketogenic diet is the cornerstone of the treatment and implicates a close monitoring by a multidisciplinary team including trained dieticians. Non-specific drugs may be used as add-on symptomatic treatments but their effects are often disappointing.
  
  
  CONCLUSIONS
  Glucose transporter type 1 deficiency syndrome is likely under diagnosed due to its complex and pleiotropic phenotype. Proper identification of the affected patients is important for clinical practice since the disease is treatable.
authors.affiliation: Service de neuropédiatrie et maladies métaboliques, hôpital Robert-Debré, 48, boulevard Sérurier, 75935 Paris cedex 19, France; Inserm UMR S975, CNRS UMR7225, centre de recherche de l'institut du cerveau et de la moelle, groupe hospitalier Pitié-Salpêtrière, bâtiment ICM, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France.
authors.forename: D
authors.initials: D
authors.lastname: Gras
authors.affiliation: Service de neuropédiatrie et maladies métaboliques, hôpital Robert-Debré, 48, boulevard Sérurier, 75935 Paris cedex 19, France; Inserm UMR S975, CNRS UMR7225, centre de recherche de l'institut du cerveau et de la moelle, groupe hospitalier Pitié-Salpêtrière, bâtiment ICM, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Département de neurologie, hôpital Pitié-Salpêtrière, 47-83, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Université Pierre-et-Marie-Curie, Paris-6, 4, place Jussieu, 75005 Paris, France. Electronic address: emmanuel.roze@psl.aphp.fr.
authors.forename: E
authors.initials: E
authors.lastname: Roze
authors.affiliation: Département de neurologie, hôpital Pitié-Salpêtrière, 47-83, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Service de génétique, hôpital Pitié-Salpêtrière, 47-83, boulevard de l'Hôpital, 75651 Paris cedex 13, France.
authors.forename: S
authors.initials: S
authors.lastname: Caillet
authors.affiliation: Inserm UMR S975, CNRS UMR7225, centre de recherche de l'institut du cerveau et de la moelle, groupe hospitalier Pitié-Salpêtrière, bâtiment ICM, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Université Pierre-et-Marie-Curie, Paris-6, 4, place Jussieu, 75005 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Méneret
authors.affiliation: Service de neuropédiatrie, hôpital Trousseau, 26, avenue du Docteur-Arnold-Netter, 75012 Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Doummar
authors.affiliation: Service de neuropédiatrie, hôpital Trousseau, 26, avenue du Docteur-Arnold-Netter, 75012 Paris, France.
authors.forename: T
authors.initials: T
authors.lastname: Billette de Villemeur
authors.affiliation: Inserm UMR S975, CNRS UMR7225, centre de recherche de l'institut du cerveau et de la moelle, groupe hospitalier Pitié-Salpêtrière, bâtiment ICM, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Département de neurologie, hôpital Pitié-Salpêtrière, 47-83, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Université Pierre-et-Marie-Curie, Paris-6, 4, place Jussieu, 75005 Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Vidailhet
authors.affiliation: Inserm UMR S975, CNRS UMR7225, centre de recherche de l'institut du cerveau et de la moelle, groupe hospitalier Pitié-Salpêtrière, bâtiment ICM, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Université Pierre-et-Marie-Curie, Paris-6, 4, place Jussieu, 75005 Paris, France; Service de génétique, hôpital Pitié-Salpêtrière, 47-83, boulevard de l'Hôpital, 75651 Paris cedex 13, France.
authors.forename: F
authors.initials: F
authors.lastname: Mochel
mesh_terms: D002239:Carbohydrate Metabolism, Inborn Errors / Q000175:diagnosis / Q000235:genetics / Q000628:therapy; D055423:Diet, Ketogenic / Q000379:methods; D051272:Glucose Transporter Type 1 / Q000235:genetics; D006801:Humans; D009004:Monosaccharide Transport Proteins / Q000172:deficiency* / Q000235:genetics; D010641:Phenotype; D008063:Thioctic Acid / Q000627:therapeutic use; D014280:Triglycerides / Q000627:therapeutic use
chemical_list: D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C495677:SLC2A1 protein, human; D014280:Triglycerides; C531010:triheptanoin; D008063:Thioctic Acid
keywords: Epilepsy; Ketogenic diet; Mental retardation; Mouvements anormaux; Movement disorders; Retard mental; Régime cétogène; SLC2A1; Épilepsie