GLUT1 deficiency syndrome is a rare genetic disorder caused by mutations in the SLC2A1 gene, which is responsible for producing the GLUT1 protein. This protein helps transport glucose across the blood-brain barrier, essential for brain function. When GLUT1 is deficient, the brain does not receive enough glucose, leading to various neurological symptoms. Symptoms of GLUT1 deficiency can include seizures, developmental delays, and movement disorders. Diagnosis typically involves genetic testing and measuring glucose levels in the cerebrospinal fluid. Treatment often includes a high-fat, low-carbohydrate diet, similar to the ketogenic diet, to help provide alternative energy sources for the brain.