Updated: Apr 25, 2021
About Glut1 Deficiency
Glut1 Deficiency is a rare, genetic disorder that impairs brain metabolism. Glucose isn’t properly transported into the brain, leaving it starving for the metabolic fuel it needs to grow, develop, and function normally and causing a wide range of neurological symptoms. Glut1 Deficiency is caused by loss of function mutations in the SLC2A1 gene, which regulates production and activity of the glucose transporter protein type 1 (Glut1). Although the vast majority of patients are affected by autosomal dominant mutations, there have been very rare instances of recessive inheritance patterns. Glut1 is the only transport protein that moves glucose across the blood brain barrier, where the brain uses it as its main source of energy. Without enough glucose, brain growth and function are impaired, resulting in symptoms that can vary widely between individuals and may change over time as a patient ages. Puberty often brings changes in symptoms and treatment response. Ketogenic diets are the standard of care and help improve most symptoms for most patients, although challenges remain..
Glut1 Deficiency Clinical Features
Symptoms may be present all the time, occur as temporary episodes, and may fluctuate in severity. Not all patients experience all symptoms, especially in milder cases. The range of symptoms may vary from mild to severe, sometimes making Glut1 Deficiency difficult to diagnose. Any combination of suggestive symptoms in any range of severity should be considered for diagnostic workup.
Most people with Glut1 Deficiency have some form of complex movement disorder. Movement disturbances tend to become the dominant feature in adolescence and adulthood, and new types of movement episodes may appear.
Seizures are common but not always present, and multiple types of seizures may occur with both focal and generalized onset. Typically, seizures first begin in infancy or early childhood and tend to stabilize, decline, and sometimes eventually resolve beyond puberty and into adulthood. Most seizures in Glut1 Deficiency are not easily treated with medication.
Cognition & Learning
Most patients experience some degree of intellectual disability ranging from subtle learning difficulties to severe intellectual disabilities.
These symptoms affect relations with other people and may include short attention span, obstinance, and delays in achieving age-appropriate behaviors. Some patients have been additionally diagnosed with attention deficit and/or autism spectrum disorders. Anxiety, obsessive-compulsive tendencies, mood disorders, and behavioral outbursts are also reported. Sociability, however, is often a strength in many Glut1 Deficiency patients.
Global developmental delays, including speech and language, are typical due to the many symptoms experienced.
Additional Possible Symptoms:
• Migraines • Episodic confusion • Lack of physical endurance or stamina • Microcephaly • Memory problems • Sleep disturbances • Cyclic vomiting Possible
Symptoms can be triggered or worsened by excessive exercise, illness, hunger, weather and temperature changes, hormones, fatigue, anxiety, excitement, and other strong emotional reactions.
Get to Know Glut1 Deficiency Foundation
The mission of the Glut1 Deficiency Foundation is to improve the quality of life for those in the Glut1 Deficiency community through increased awareness, improved education, advocacy for patients and families, and support and funding for research. All of our organization's activities and service programs revolve around this mission, and we serve a global patient population. The Glut1 Deficiency Foundation is led by parents of patients and was formed originally in 2009 – born of a desire for Glut1 families to get together to meet, share, and learn from one another. Glut1 Deficiency is such a rare diagnosis that many families, and especially our Glut1 children, have never had the experience of meeting others who share this journey. We received formal 501c3 status in 2011.
I am especially proud of ...
We work hard to be inclusive and representative of the diverse experiences in our patient community and be a voice for all. We have also worked hard to build mutual trust and respect with our clinical and research community as well. We've hosted eight very successful and growing family conferences, and we plan our first scientific meeting in 2021. We have an engaged and motivated community who has helped raise funds for the $814,000 the Glut1 Deficiency Foundation has provided in research support.
Excited to REN because...
We know that all of us can do so much more together than any of us can do alone, so it helps all of us to collaborate and join efforts when possible to magnify and accelerate both our individual and collective progress. There are many shared challenges among the REN community, and very likely the pathway to effective treatments and quality of life can be shared by many of us as well. We look forward to working with other patient communities to bring a brighter future for all of us.
My journey and motivation...
My daughter, Macie, now a young adult, was diagnosed with Glut1 Deficiency when she was 10. She had classic symptoms and was under the care of great doctors at great institutions, but none of them had ever heard of Glut1 Deficiency, or if they had heard of it, what they knew was wrong or outdated. The focus then was on treating symptoms, too, and not trying to understand the underlying causes. For our Glut1 Deficiency patients, knowing the underlying cause is essential as it leads to an effective treatment (ketogenic diets) and helps avoid the merry-go-round of ineffective ones. Thankfully, we had turned to the diet years before the diagnosis as a way to try to control the seizures, and in doing so we unknowingly also helped preserve her brain growth and development. When we finally had a proper diagnosis, everything made sense. We quickly found a community - or a family, really - of others who shared similar journeys. It was these shared experiences that were the driving force to establishing the Glut1 Deficiency Foundation - wanting to help our own children, but also help those following after and hoping to end the long diagnostic odyssey for so many.
By Glenna Steele - Founding Board Member, Executive Director