title: New Paradigm for the Treatment of Glucose Transporter 1 Deficiency Syndrome: Low Glycemic Index Diet and Modified High Amylopectin Cornstarch.
abstract: OBJECTIVE
  Glucose transporter 1 deficiency syndrome is an autosomal, dominantly inherited neurometabolic disorder caused by mutations in the SLC2A1 gene. Decreased glucose transport into the brain results in seizures and cognitive dysfunction. The ketogenic diet is the treatment of choice, but complicated with compliance problems. Stabilization of blood glucose levels by low glycemic index diet and modified high amylopectin cornstarch would provide steady-state glucose transport into the brain to prevent seizures and cognitive dysfunction in patients with glucose transporter 1 deficiency syndrome as an alternative treatment.
  
  
  METHODS
  We report a new glucose transporter 1 deficiency syndrome patient (c.988C>T; p. Arg330X in the SLC2A1) treated with modified high amylopectin cornstarch (Glycosade) and low glycemic index diet because of compliance problems with the ketogenic diet. She was diagnosed at 11.5 years of age and was treated with the ketogenic diet between ages 12 and 18 years.
  
  
  RESULTS
  She was started on modified high amylopectin cornstarch at bedtime and low glycemic index diet with meals and snacks every 3-4 hours. Within the first 6 months of therapy, she improved in her seizures and cognitive functions, but experienced compliance problems afterwards. Neuropsychological assessment was stable at 12 months of therapy.
  
  
  CONCLUSIONS
  This diet was easy to apply compared with the ketogenic diet and resulted in stable neuropsychological functioning of this glucose transporter 1 deficiency syndrome patient. Modified high amylopectin cornstarch and low glycemic index diet might be an alternative treatment in glucose transporter 1 deficiency syndrome patients with compliance problems to the ketogenic diet treatment, but additional patients should be treated to prove usefulness of this new treatment.
authors.affiliation: Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Canada; Division of Pediatric Neurology, Montreal Children's Hospital-McGill University Health Center, Montreal, Canada; Division of Pediatric Neurology, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Almuqbil
authors.affiliation: Division of Neurology, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Cristina
authors.initials: C
authors.lastname: Go
authors.affiliation: Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Canada; Department of Clinical Dietetics, University of Toronto, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Nagy
authors.affiliation: Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Canada; Department of Clinical Dietetics, University of Toronto, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Nisha
authors.initials: N
authors.lastname: Pai
authors.affiliation: Department of Psychology, University of Toronto, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Eva
authors.initials: E
authors.lastname: Mamak
authors.affiliation: Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Canada; Genetics and Genome Biology Research Program, Research Institute, The Hospital for Sick Children, Toronto, Canada. Electronic address: saadet.mahmutoglu@sickkids.ca.
authors.forename: Saadet
authors.initials: S
authors.lastname: Mercimek-Mahmutoglu
mesh_terms: D002239:Carbohydrate Metabolism, Inborn Errors / Q000178:diet therapy* / Q000235:genetics / Q000503:physiopathology / Q000523:psychology; D055423:Diet, Ketogenic; D051272:Glucose Transporter Type 1 / Q000172:deficiency* / Q000235:genetics; D038321:Glycemic Index; D006801:Humans; D009004:Monosaccharide Transport Proteins / Q000172:deficiency*; D009483:Neuropsychological Tests; D013213:Starch / Q000008:administration & dosage*; D013577:Syndrome; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C495677:SLC2A1 protein, human; D013213:Starch
keywords: GLUT-1 deficiency syndrome; compliance; ketogenic diet; low glycemic index diet; modified high amylopectin cornstarch (Glycosade)