title: Nationwide survey of glucose transporter-1 deficiency syndrome (GLUT-1DS) in Japan.
abstract: OBJECTIVE
  We conducted a nationwide survey of glucose transporter type-1 deficiency syndrome (GLUT-1DS) in Japan in order to clarify its incidence as well as clinical and laboratory information.
  
  
  METHODS
  A questionnaire to survey the number of genetically and clinically confirmed cases of GLUT-1DS was sent to 1018 board-certified pediatric neurologists, which resulted in 57 patients being reported. We obtained the clinical and laboratory data of 33 patients through a secondary questionnaire.
  
  
  RESULTS
  The age of the 33 patients (male: 15, female: 18) at the time of the study ranged between 3 and 35 years (mean: 13.5 years). The age of these patients at the onset of initial neurological symptoms ranged between the neonatal period and 48 months (mean: 9.4 months). GLUT-1DS was diagnosed at a mean age of 8.4 years (range: 1 year to 33 years). The initial symptom was convulsive seizures, which occurred in 15 cases, and was followed by abnormal eye movements in 7 cases and apneic or cyanotic attacks in 4 cases. The latter two symptoms most frequently occurred early in infancy. Thirty-two patients (97%) exhibited some type of epileptic seizure. Neurological findings revealed that most patients had muscle hypotonia, cerebellar ataxia, dystonia, and spastic paralysis. Mild to severe mental retardation was detected in all 33 cases. Furthermore, paroxysmal episodes of ataxia, dystonia/dyskinesia, and motor paralysis were described in approximately 1/3 of all patients. The factors that frequently aggravated these events were hunger, exercise, fever, and fatigue, in that order. The mean CSF/blood glucose ratio was 0.36 (0.28-0.48). Pathological mutations in the SLC2A1 gene were identified in 28 out of 32 cases (87.5%).
  
  
  CONCLUSIONS
  The results described herein provided an insight into the early diagnosis of GLUT1-DS, including unexplained paroxysmal abnormal eye movements, apneic/cyanotic attacks, and convulsive seizures in infancy, as well as uncommon paroxysmal events (ataxia, atonia, and motor paralysis) in childhood.
authors.affiliation: Department of Pediatrics, Tokyo Women's Medical University, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Pediatrics, Asahikawa Medical University, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: United Graduate School of Child Development, Osaka University Graduate School of Medicine, Japan.
authors.forename: Kuriko
authors.initials: K
authors.lastname: Kagitani-Shimono
authors.affiliation: Department of Pediatrics, Nagoya University, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Natsume
authors.affiliation: Section of Pediatric Neurology, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yanagihara
authors.affiliation: Shiga Medical Center for Children, Shiga, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Department of Pediatrics, Tokyo Women's Medical University, Japan. Electronic address: hoguni@ped.twmu.ac.jp.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Oguni
mesh_terms: D000293:Adolescent; D000328:Adult; D002239:Carbohydrate Metabolism, Inborn Errors / Q000453:epidemiology* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005260:Female; D051272:Glucose Transporter Type 1 / Q000235:genetics; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000172:deficiency* / Q000235:genetics; D011795:Surveys and Questionnaires
chemical_list: D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C495677:SLC2A1 protein, human
keywords: Epilepsy; Glucose transporter type-1; Hypoglycorrhachia; Ketogenic diet; Movement disorders