title: A three-year-old boy with glucose transporter type 1 deficiency syndrome presenting with episodic ataxia.
abstract: BACKGROUND
  Glucose transporter type 1 deficiency syndrome is a metabolic encephalopathy that results from impaired glucose transport into the brain as the result of a mutation of the SLC2A1 gene. It has been recognized recently that these patients can present with a much broader clinical spectrum than previously thought. We describe a 3-year-old boy presenting with episodic ataxia.
  
  
  METHODS
  Our patient exhibited periodic abnormal eye movements, including opsoclonus, since he was 4 months of age. At 2 years of age, he experienced acute cerebellar ataxia after a vaccination. Since then, he has had periodic attacks of ataxic gait, repeated vomiting, and abnormal eye movement. He was diagnosed as having episodic ataxia type 2 because the administration of acetazolamide seemed effective. By 3 years and 10 months of age, he exhibited mild mental retardation and mild trunk ataxia. The attacks were more likely to occur when he was hungry. Molecular analysis revealed that the SLC2A1 gene had a de novo mutation of heterozygous seven nucleotide insertion within exon 7, resulting in a frameshift. He has recently begun a modified Atkins diet; the frequency of attacks has been reduced, and his psychomotor and language skills have begun to develop.
  
  
  CONCLUSIONS
  Glucose transporter type 1 deficiency syndrome should be considered in the differential diagnosis in children with episodic ataxia, even if acetazolamide is effective.
authors.affiliation: Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Ohshiro-Sasaki
authors.affiliation: Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Shimbo
authors.affiliation: Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Takano
authors.affiliation: Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan. Electronic address: takahito.wada0001@me.com.
authors.forename: Takahito
authors.initials: T
authors.lastname: Wada
authors.affiliation: Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Osaka
mesh_terms: D001928:Brain Diseases, Metabolic / Q000150:complications*; D002524:Cerebellar Ataxia / Q000150:complications*; D002675:Child, Preschool; D051272:Glucose Transporter Type 1 / Q000172:deficiency* / Q000235:genetics; D006801:Humans; D008297:Male
chemical_list: D051272:Glucose Transporter Type 1
keywords: SLC2A1; cerebellar ataxia; episodic ataxia; glucose transporter type 1 deficiency syndrome; intellectual disability; ketogenic diet; seizure