GLUT1 deficiency syndrome is a disorder that primarily affects the brain. Affected individuals generally have seizures beginning in the first few months of life. Babies with GLUT1 deficiency syndrome have a normal head size at birth, but growth of the brain and skull is often slow, in severe cases resulting in an abnormally small head size (microcephaly).
People with GLUT1 deficiency syndrome may have developmental delay, learning disabilities, or mental retardation. They may also have other neurological problems, such as stiffness caused by abnormal tensing of the muscles (spasticity), difficulty in coordinating movements (ataxia), and speech difficulties (dysarthria). Some experience episodes of confusion, lack of energy (lethargy), headaches, muscle twitches (myoclonus), or involuntary irregular eye movements, particularly before meals.
GLUT1 deficiency syndrome is a rare disorder. Fewer than 100 cases have been reported since the disorder was first identified in 1991.
The SLC2A1 gene provides instructions for producing a protein called the glucose transporter protein type 1 (GLUT1). This protein is part of the membranes of cells, where it transports glucose (a simple sugar) from the blood into the cells for use as fuel.
Glucose transporter protein type 1 is involved in moving glucose across the blood-brain barrier, which is the boundary that separates tiny blood vessels (capillaries) from the surrounding brain tissue. Glucose is the brain's main energy source under normal conditions. The blood-brain barrier protects the brain's delicate nerve tissue by preventing many other types of molecules from entering the brain.
SLC2A1 mutations reduce or eliminate the function of the glucose transporter protein type 1 produced from one copy of the gene in each cell. Reduced transporter function lessens the availability of glucose, resulting in the signs and symptoms of GLUT1 deficiency syndrome.
Read more about the SLC2A1 gene.
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.
Most cases of this disorder result from new mutations in the gene. These cases occur in people with no history of the disorder in their family. In some cases, an affected person inherits the mutation from an affected parent.
These resources address the management of GLUT1 deficiency syndrome and may include treatment providers.
You might also find information on treatment of GLUT1 deficiency syndrome in
Educational resources and Patient support.
You may find the following resources about GLUT1 deficiency syndrome helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
- De Vivo disease
- encephalopathy due to GLUT1 deficiency
- glucose transport defect, blood-brain barrier
- glucose transporter protein syndrome
- glucose transporter type 1 deficiency syndrome
- GLUT1 DS
The resources on this site should not be used as a substitute for
professional medical care or advice. Users seeking information about
a personal genetic disease, syndrome, or condition should consult with a qualified
See How can I find a genetics professional in my area? in the Handbook.