GLUT1 Deficiency is caused by variants or mutations in the SLC2A1 gene, although not all patients will have a genetic variant detected on current testing. The SLC2A1 gene is responsible for producing and regulating the glucose transporter type 1 protein (GLUT1).  GLUT1 is responsible for moving glucose across the blood brain barrier. Glucose is a primary source of energy for all cells and plays a vital role in brain metabolism. When there isn’t enough GLUT1 or it isn’t functioning properly, glucose doesn’t reach the brain as well as it should, and many neurological symptoms result.

There is a wide range of symptom severity, and not every person with GLUT1 Deficiency experiences the same symptoms, so this makes it difficult to predict what an individual experience and future might hold. Some patients are very mildly affected with just a symptom or two and are able to lead an independent life, while others are quite severely impacted and might be unable to walk, talk, or function independently. Most fall somewhere in between. 

It is also important to remember that less is known about the adult experiences in GLUT1 Deficiency, especially later in life.  Symptoms and severity do not seem to be progressive over the lifespan, although there can be fluctuation in severity and change in symptoms as patients age. There is no known impact on life expectancy, although there are increased risks associated with any type of epilepsy for seizure related deaths or SUDEP (Sudden Unexplained Death in Epilepsy).

The good news is that most people with GLUT1 Deficiency, regardless of age, respond well to a ketogenic diet and experience improvement in many symptoms. There are many ketogenic diet resources and links available on our website.

There is no cure for GLUT1 Deficiency, so treatment is aimed at managing symptoms. The current standard of care is a medically supervised ketogenic diet.  Ketogenic diets are high fat, moderate protein, and low carbohydrate diets that cause the body to produce ketones, which the brain can use as a fuel source when glucose is limited. There are likely other mechanisms at work in explaining how ketogenic diets can help the symptoms of GLUT1 Deficiency, but those are not yet well understood.

Research has shown that the earlier someone is diagnosed with GLUT1 Deficiency and begins treatment with a ketogenic diet, the better the outcomes. There is research underway to identify other options for patients and families for easier and more complete treatments as well as for those who many not respond well to a ketogenic diet.

Additionally, other types of support are beneficial in treating GLUT1 Deficiency, such as speech and language, occupational, and physical therapies. Special supports and plans in place in the classroom (such as IEP’s, Individualized Education Plans, and 504 plans) are also very helpful in optimizing academic success and the overall school experience, and special accommodations in the workplace can also be important forms of support.

GLUT1 Deficiency is a rare disease, and currently we believe there are about 2,000 people diagnosed worldwide. Without a formal way to report and track patients, it is very difficult to know exact numbers, and that is one of the reasons why projects like the GLUT1 Deficiency Natural History Study is so important. Recent research has also estimated that the true prevalence is at least 1 in 24,000, which means there are many more people still to find who need a life-changing diagnosis.

Take some time to come to terms with this new diagnosis and what it means for you and your family. It often comes as a big relief to have answers, but there can also be a grieving process that is important to acknowledge. Once you are ready, there are many ways you can empower yourself on this new journey and put your hope for a brighter future into action.  Look through our many resources to find information and opportunities to help you better understand this disease and help you be an advocate for you, your loved one, and everyone in the GLUT1 Deficiency community.

Most cases of GLUT1 Deficiency are caused by a de novo variant or mutation, which just means it is a new, spontaneous one that happened for the first time with no known cause. This means that neither parent has the genetic variant and it wasn’t inherited.  However, when someone is affected by GLUT1 Deficiency and has a genetic variant, it can be passed on to offspring with each child having a 50% chance of inheriting the disease from their parent. It is an autosomal dominant inheritance pattern, which means it only takes one mutated copy of the gene (out of two) to cause disease.

Talk to your doctors about your diagnosis and create partnerships when possible.  You will be the expert in many circumstances, so it is important that you understand this disease well, keep up with new advancements and research, and feel confident in being an advocate for yourself or your child. The GLUT1 Deficiency Foundation can send brochures for you to share with your healthcare team, and the expert consensus guidelines are another helpful resource to share. You can also send them to this website for additional resources, and even invite them to join our Professional Network and attend one of our conferences!

We have created a directory of healthcare providers who have been recommended by GLUT1 Deficiency families for their experience, compassion, and the quality of care they provide. You may find that Family Recommended Specialist List here. It is also important to remember that a willingness to learn about a disease and a commitment to caring for patients well can be a good substitute for experience, so you can help create the next generation of GLUT1 Deficiency experts through partnerships and collaborations with your healthcare team.

The GLUT1 Deficiency community is like a family, and you’ll find many who are eager to welcome you and help you on this new journey. We have created a secure, private Facebook group where you can connect with other families, ask questions, share ideas, and give and get support – GLUT1 Community Connect.  You can also join our regular GLUT1 Gatherings on Zoom to learn and meet families from all over the world, or if you are a tween/teen or adult living with GLUT1 Deficiency, you can join monthly meetings for your age group.  Every other year, we host our conference where we meet, share, and learn with patients, families, clinicians, researchers, and other stakeholders who are working hard to help us all build a brighter future.