GLUT1 Deficiency SLC2A1 Gene Analysis Test Cost & Procedure

It is a rare hereditary condition called GLUT1 deficiency. Variants in the SLC2A1 gene are the cause. SLC2A1 gives instructions for GLUT1 production. The GLUT1 protein helps the brain's cerebrospinal fluid (CSF), which surrounds the brain, absorb glucose from the blood.

Reduced glucose transfer into the brain is a symptom of the autosomal dominant haploinsufficiency disorder known as glucose transporter-1 (GLUT1) deficiency syndrome. The blood-brain barrier and erythrocyte endothelial cells, which express GLUT1 in high levels, are the only places where glucose is transported into the brain.

Whenever GLUT1 deficient syndrome is suspected clinically, a fasting lumbar puncture should be done. Hypoglycorrhachia, or low glucose concentration in the cerebrospinal fluid in the absence of hypoglycemia, together with low to normal lactate levels are the hallmarks of the GLUT1 deficient syndrome.

Testing Plan

The SLC2A1 gene is fully covered by this test, along with around 10 bases of flanking noncoding DNA. Full coverage is defined as Sanger sequencing or >20X NGS reads.

Test Suggestions

Individuals with GLUT1 Deficiency Syndrome are suitable candidates for this test, especially if it has been shown that they have a low blood glucose concentration ratio and a low concentration of glucose in their CSF. Individuals who have additionally shown diminished erythrocyte glucose absorption in the 3-O-methyl-D-Glucose (3-OMG) assay are particularly qualified candidates. Family relatives of patients with known SLC2A1 mutations make suitable candidates for this test. Also, we will sequence the SLC2A1 gene to establish carrier status and validate our findings.

Clinical Characteristics

Defective glucose transport into the brain results in GLUT1 Deficiency Syndrome (GLUT1-DS, sometimes called De Vivo Syndrome). The classic phenotype is defined by infantile-onset seizures that are frequently refractory, delayed neurological growth, acquired microcephaly, and complicated movement abnormalities, which typically include ataxia, dystonia, and chorea. Seizures start in about 90% of people with classic GLUT1-DS before the age of two, while in the other 10% they start later in life.

Cognitive impairment is a common finding and can range from modest learning impairments to profound intellectual disability. Complex movement disorders can be continuous or paroxysmal, and environmental circumstances like hunger, fever, exercise, or worry can have an impact on how severe they are.