Mutational and functional analysis of Glucose transporter I deficiency syndrome

Mol Genet Metab. 2015 Nov;116(3):157-62. doi: 10.1016/j.ymgme.2015.08.006. Epub 2015 Aug 14.

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.

Keywords: 2-deoxyglucose uptake; Functional assay; GLUT1; Glucose transporter I deficiency syndrome (GLUT1-DS); SLC2A1.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Carbohydrate Metabolism, Inborn Errors / genetics*
  • Carbohydrate Metabolism, Inborn Errors / physiopathology*
  • Deoxyglucose / metabolism
  • Frameshift Mutation*
  • Genotype
  • Glucose Transporter Type 1 / genetics*
  • HEK293 Cells
  • Humans
  • Male
  • Monosaccharide Transport Proteins / deficiency*
  • Monosaccharide Transport Proteins / genetics
  • Sequence Analysis, DNA

Substances

  • Glucose Transporter Type 1
  • Monosaccharide Transport Proteins
  • SLC2A1 protein, human
  • Deoxyglucose

Supplementary concepts

  • Glut1 Deficiency Syndrome