title: Mutational and functional analysis of Glucose transporter I deficiency syndrome.
abstract: OBJECTIVE
  We investigated a correlation between a mutation in the SLC2A1 gene and functional disorders in Glucose transporter I deficiency syndrome (GLUT1DS).
  
  
  METHODS
  We performed direct sequence analysis of SLC2A1 in a severe GLUT1DS patient and identified a novel frame shift mutation, c.906_907insG, p.V303fs. We created a plasmid vector carrying the c.906_907insG mutation, as well as A405D or R333W in the SLC2A1, which are found in patients with mild and moderate GLUT1DS severity, respectively. We transiently expressed these mutants and wild type SLC2A1 plasmids in a human embryonic kidney cell line (HEK293), and performed immunoblotting, immunofluorescence, and enzymatic photometric 2-deoxyglucose (2DG) uptake assays.
  
  
  RESULTS
  GLUT1 was not detected after transient expression of the SLC2A1 plasmid carrying c.906_907insG by either immunoblotting or immunofluorescence. The degree of glucose transport reduction as determined by enzymatic photometric 2DG assay uptake correlated with disease severity.
  
  
  CONCLUSIONS
  Enzymatic photometric 2DG uptake study appears to be a suitable functional assay to predict the effect of SLC2A1 mutations on GLUT1 transport.
authors: Department of Pediatrics, Jichi Medical University, Tochigi, Japan.
authors: Sachie
authors: S
authors: Nakamura
authors: Department of Pediatrics, Jichi Medical University, Tochigi, Japan. Electronic address: hosaka@jichi.ac.jp.
authors: Hitoshi
authors: H
authors: Osaka
authors: Division of Neurology, Jichi Medical University, Tochigi, Japan; Center for Gene and Cell Therapy, The Institute of Medical Science, The University of Tokyo, Japan.
authors: Shinichi
authors: S
authors: Muramatsu
authors: Department of Pediatrics, Jichi Medical University, Tochigi, Japan.
authors: Shiho
authors: S
authors: Aoki
authors: Department of Pediatrics, Jichi Medical University, Tochigi, Japan.
authors: Eriko F
authors: EF
authors: Jimbo
authors: Department of Pediatrics, Jichi Medical University, Tochigi, Japan.
authors: Takanori
authors: T
authors: Yamagata
mesh_terms: D000293:Adolescent; D002239:Carbohydrate Metabolism, Inborn Errors / Q000235:genetics* / Q000503:physiopathology*; D003847:Deoxyglucose / Q000378:metabolism; D016368:Frameshift Mutation; D005838:Genotype; D051272:Glucose Transporter Type 1 / Q000235:genetics*; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000172:deficiency* / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C495677:SLC2A1 protein, human; D003847:Deoxyglucose
keywords: 2-deoxyglucose uptake; Functional assay; GLUT1; Glucose transporter I deficiency syndrome (GLUT1-DS); SLC2A1