European Glut1 Deficiency Organization

About Glut1 Deficiency

What is Glut1 Deficiency?

Glucose Transporter Type 1 Deficiency Syndrome

Glucose Transporter Type 1 Deficiency Syndrome is a genetic disorder that impairs brain metabolism. Glucose is not transported properly into the brain, which leaves it starving for the metabolic fuel it needs to grow, develop, and function the way it should.

Glut1 Deficiency is caused by mutations in the SLC2A1 gene, which is responsible for regulating production of the glucose transporter protein type 1 (Glut1). The Glut1 protein transports glucose into cells, between cells, and across the blood-brain barrier. Glut1 is the principal transporter of glucose, the primary source of energy, across the blood-brain barrier and is key in supplying glucose to the cells of the central nervous system. More than 100 different types of mutations and deletions of this gene have been found to date in Glut1 Deficiency patients, and approximately 10-15% of patients do not show a genetic mutation.

The impaired glucose transport associated with Glut1 Deficiency causes an array of symptoms which may vary considerably from one patient to another and can change and evolve over time. Some of the most common signs and symptoms may include seizures, unusual eye-head movements in infancy, movement disorders, speech and language disorders, and developmental delays. Not all patients experience all symptoms, especially in the milder cases. There are currently a few hundred patients diagnosed worldwide, but experts believe there are thousands more yet to be discovered.

How can I cure Glut1 Deficiency?

There is currently no cure for Glut1 Deficiency. The recommended standard treatment is a ketogenic diet, which helps improve most symptoms for most patients, even in adulthood. A ketogenic diet gives the brain an alternate source of energy and helps optimize brain growth and development.

What is a ketogenic diet?

The ketogenic diet is a diet high in fat and low in protein and carbohydrates, with up to 90% of calories obtained from fat. Since the diet is low in carbohydrates, the body gets little glucose, normally the main energy source. The fat in the diet is converted by the liver into ketone bodies, which causes a build up of ketones in the blood stream, called ketosis. Ketone bodies are transported across the blood-brain barrier by other means than the Glut1 protein and thus serve as an alternative fuel for the brain when glucose is not available.

Once diagnosed, a medically supervised ketogenic diet is usually recommended as it can help to control seizures. The ketogentic diet is the current standard of care treatment, effectively controlling most seizures and improving some movement disorders in approximately two thirds of Glut1 Deficiency patients.

How do you call it?

Glut1 Deficiency, G1D, Glut1 DS, or De Vivo Disease.