Glut1 Deficiency

Glut1 Deficiency (Glut1D, OMIM #606777) is caused by impaired glucose transport into the brain. The resulting cerebral “energy crisis” causes intractable seizures, developmental delay, and a complex movement disorder. The diagnosis is based on clinical features, low CSF glucose and/or mutations in the SLC2A1 gene. Paroxysmal exertion-induced dystonia (PED) and hereditary cryohydrocytosis have been described as allelic variants. Adults are increasingly being recognized through family pedigrees. The condition is effectively treatable by mimicking the metabolic state of fasting. High-fat carbohydrate-restricted ketogenic diets generate ketones that serve as an alternative fuel for the brain. In adults with Glut1D, novel modified ketogenic diets can be used, allowing more carbohydrates and greater palatability and compliance.