Skip Navigation
Home A service of the U.S. National Library of Medicine®
Printer-friendly version
GLUT1 deficiency syndrome

GLUT1 deficiency syndrome

Reviewed March 2014

What is GLUT1 deficiency syndrome?

GLUT1 deficiency syndrome is a disorder affecting the nervous system that can have a variety of neurological signs and symptoms. Approximately 90 percent of affected individuals have a form of the disorder often referred to as common GLUT1 deficiency syndrome. These individuals generally have frequent seizures (epilepsy) beginning in the first months of life. In newborns, the first sign of the disorder may be involuntary eye movements that are rapid and irregular. Babies with common GLUT1 deficiency syndrome have a normal head size at birth, but growth of the brain and skull is often slow, which can result in an abnormally small head size (microcephaly). People with this form of GLUT1 deficiency syndrome may have developmental delay or intellectual disability. Most affected individuals 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, or muscle twitches (myoclonus), particularly during periods without food (fasting).

About 10 percent of individuals with GLUT1 deficiency syndrome have a form of the disorder often known as non-epileptic GLUT1 deficiency syndrome, which is usually less severe than the common form. People with the non-epileptic form do not have seizures, but they may still have developmental delay and intellectual disability. Most have movement problems such as ataxia or involuntary tensing of various muscles (dystonia); the movement problems may be more pronounced than in the common form.

Several conditions that were originally given other names have since been recognized to be variants of GLUT1 deficiency syndrome. These include paroxysmal choreoathetosis with spasticity (dystonia 9); paroxysmal exercise-induced dyskinesia and epilepsy (dystonia 18); and certain types of epilepsy. In rare cases, people with variants of GLUT1 deficiency syndrome produce abnormal red blood cells and have uncommon forms of a blood condition known as anemia, which is characterized by a shortage of red blood cells.

How common is GLUT1 deficiency syndrome?

GLUT1 deficiency syndrome is a rare disorder. Approximately 500 cases have been reported worldwide since the disorder was first identified in 1991. In Australia, the prevalence of the disorder has been estimated at 1 in 90,000 people. However, researchers suggest that the disorder may be underdiagnosed, because many neurological disorders can cause similar symptoms.

What genes are related to GLUT1 deficiency syndrome?

GLUT1 deficiency syndrome is caused by mutations in the SLC2A1 gene. This gene provides instructions for producing a protein called the glucose transporter protein type 1 (GLUT1). The GLUT1 protein is embedded in the outer membrane surrounding cells, where it transports a simple sugar called glucose into cells from the blood or from other cells for use as fuel.



Read more about the SLC2A1 gene.

How do people inherit GLUT1 deficiency syndrome?

This condition is usually inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. About 90 percent of cases of GLUT1 deficiency syndrome result from new mutations in the gene. These cases occur in people with no history of the disorder in their family. In other cases, an affected person inherits the mutation from an affected parent.


Where can I find information about diagnosis or management of GLUT1 deficiency syndrome?

These resources address the diagnosis or management of GLUT1 deficiency syndrome and may include treatment providers.

You might also find information on the diagnosis or management of GLUT1 deficiency syndrome in Educational resources and Patient support.



Where can I find additional information about GLUT1 deficiency syndrome?

You may find the following resources about GLUT1 deficiency syndrome helpful. These materials are written for the general public.


What other names do people use for GLUT1 deficiency syndrome?

  • De Vivo disease
  • encephalopathy due to GLUT1 deficiency
  • G1D
  • glucose transport defect, blood-brain barrier
  • glucose transporter protein syndrome
  • glucose transporter type 1 deficiency syndrome
  • Glut1 deficiency
  • GLUT1 DS
  • GTPS


What if I still have specific questions about GLUT1 deficiency syndrome?

Where can I find general information about genetic conditions?

What glossary definitions help with understanding GLUT1 deficiency syndrome?

References (11 links)



Reviewed: March 2014
Published: June 29, 2015