Institutional Price 
4 weeks
CPT Code 
Test Code 
Test Methods 
Deletion/Duplication analysis
Specimen Types Accepted 
Cultured Cells
Extracted DNA

Glucose transporter type 1 deficiency syndrome (GLUT1DS) is characterized by infantile-onset epileptic encephalopathy associated with delayed development, acquired microcephaly, motor incoordination, and spasticity. Seizures typically begin within the first 4 months of life following a normal birth and gestation. Glucose concentration in cerebrospinal fluid should be the first test considered in patients suspected of having GLUT1DS. Hypoglycorrhachia (low CSF glucose, less than 40mg/dl) is practically diagnostic for this disorder. Calculation of the ratio of CSF glucose concentration to blood glucose concentration is consistently about 0.33±0.01 (normal ratio: 0.65±0.01). Mutations of the Solute Carrier Family 2, Member 1 (SLC2A1) have been identified in patients with GLUT1DS. The SLC2A1 gene maps to 1q35 and has 10 coding exons. Sequencing of SLC2A1 detects mutations in approximately 91% of affected individuals. We offer full gene sequencing of all 10 coding exons and intron/exon boundaries of SLC2A1 by direct sequencing of amplification products in both the forward and reverse directions. SLC2A1 sequencing is also available as part of our Early Infantile Epileptic Encephalopathy (EIEE) panel. Please see our information sheet for more details.