title: Glucose transporter type 1 deficiency due to SLC2A1 gene mutations--a rare but treatable cause of metabolic epilepsy and extrapyramidal movement disorder; own experience and literature review.
abstract: OBJECTIVE
  To present the molecular and clinical characteristics of three children with glucose deficiency syndrome, an inborn rare metabolic disease, caused by mutations in the SLC2A1 gene.
  
  
  METHODS
  The investigation was carried out in three children: two girls and one boy showing symptoms of GLUT1 deficiency syndrome (GLUT1-DS). They were referred for SLC2A1 gene analysis.
  
  
  RESULTS
  The presence of mutations in all of them was confirmed. Only point mutations were identified, two missenses p.Gly132Ser, p.Arg212Cys and amino acid insertion p.Ser_Val227insValProPro. In two cases the mutations arose de novo, one was heritable of paternal origin.
  
  
  CONCLUSIONS
  GLUT1-DS shows high clinical variability. It should be suspected in children of any age presenting with single features or a combination of any form of intractable epilepsy with seizures of various types, movement disorders and paroxysmal events, especially triggered by exercise, exertion, or fasting, and any unexplainable neurological deterioration. The basic diagnostic hallmarks of GLUT1-DS are CSF hypoglycorrhachia and lowered CSF/Blood serum glucose ratio. This is why lumbar punction should be considered more frequently than it is in practice being performed nowadays. Antiepileptic drug treatment may be ineffective or even potentially detrimental. Early identification and molecular confirmation of GLUT1-DS is important, because this is a metabolic disorder and patients should as soon as possible primarily be treated with a ketogenic diet.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Szczepanik
authors.affiliation: Clinic of Neurology of Child and Adolescents, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland, tel. (+48 22) 32-77-307, fax (+48 22) 32-77-130, e-mail: iwonaterczynska@onet.eu.
authors.forename: Iwona
authors.initials: I
authors.lastname: Terczyńska
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Kruk
authors.forename: Agata
authors.initials: A
authors.lastname: Lipiec
authors.forename: Ewa
authors.initials: E
authors.lastname: Dudko
authors.forename: Jolanta
authors.initials: J
authors.lastname: Tryfon
authors.forename: Marta
authors.initials: M
authors.lastname: Jurek
authors.forename: Dorota
authors.initials: D
authors.lastname: Hoffman-Zacharska
mesh_terms: D002648:Child; D004252:DNA Mutational Analysis; D004827:Epilepsy / Q000235:genetics*; D005260:Female; D051272:Glucose Transporter Type 1 / Q000172:deficiency* / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D019636:Neurodegenerative Diseases / Q000235:genetics
chemical_list: D051272:Glucose Transporter Type 1; C495677:SLC2A1 protein, human