Watching my son, Brennan, struggle to meet development milestones through the first two years of his life was possibly one of the most difficult things I’ve had to endure as a mother. When others were taking their first steps, Brennan remained seated. Though my husband and I worried, we tried to remain calm. “Everything will be fine,” doctors told us. “Every child develops at his or her own pace.” Sure enough, even though Brennan struggled, he was barely meeting his developmental milestones so, together with our pediatrician, we ever remained vigilant of his development.

But when Brennan had still not taken his first steps at 15 months, we made the decision to take him to physical therapy. Much to our relief, he began walking just in time for his 18-month checkup. But within weeks, we observed a new cause for concern. Brennan’s arm now hung awkwardly at his side when he walked; like a bird with a broken wing. Searching for answers, our doctor encouraged us to see a neurologist who knew that something was wrong within two minutes of observation.

“Your child has dystonia,” he said. “We need to do a lumbar puncture.” My heart sank. I’d just been told that my dear boy had something I’d never even heard of before, and doctors—who couldn’t tell me what was wrong with him—needed to perform a spinal tap test that involves the extraction of some of the fluid that surrounds the brain and spinal cord.

But after initiating the process, we began to get answers. The lumbar puncture confirmed Brennan had low glucose levels, prompting our neurologist to call for a genetic test to determine if Brennan was suffering from Glut1 Deficiency Syndrome, an extremely rare condition that prevents an adequate amount of glucose from getting to the brain. Shortly after, the test results came back positive for this disease that affects only 1 in 90,000 births.

Equipped with a diagnosis, we sought expert opinions to land on a course of potential treatment for our family. That’s when we learned how lucky we really were. We learned that many patients with Glut1 DS go either undiagnosed or are misdiagnosed. Since many children with Glut1 DS have seizures, they are commonly diagnosed with epilepsy.

Today, Brennan’s symptoms are under control thanks to this prompt diagnosis. Mothers are their child’s best advocate with instincts that tell us when to keep searching for answers. As a parent, no one knows your child better than you, which is why it’s so important to ask questions, talk to your doctors about your child’s symptoms and explore available genetic testing options.

If you are concerned about your child, talk to your doctor and ask if genetic testing for Glut1 DS is appropriate for your child.

For more information, please visit

Lisa Moore, the mother of Brennan, a three-year-old boy who has a rare condition called Glucose Transporter Type 1 deficiency syndrome (Glut1 DS) is an advocate for the early diagnosis of Glut1 and genetic testing. Her compelling story may give hope to other parents who have a child with a rare disease. Thanks to genetic testing, Brennan was diagnosed with Glut1 Deficiency Syndrome, a rare genetic disorder. Armed with this diagnosis, Brennan’s parents and medical team developed an effective plan to potentially control his symptoms. Happily, today Brennan is active and enjoying his new-found freedom as a three year old.



• Rare genetic disorder caused by a mutation affecting the gene that codes for Glut1, which is a protein that transports glucose from blood into the brain
• Results in a chronic state of energy deficiency in the brain
• Patients may experience seizures, developmental delay and movement disorder
• Many go undiagnosed or misdiagnosed, most commonly with epilepsy
• There are no approved treatments, but it can be managed through a specialized diet

Leave a Reply