Dietary treatment of Glucose Transporter Type 1 Deficiency (G1D).

This is an open-label, single arm trial of orally-administered C7 in G1D. Subjects will replace a fixed percentage of their daily caloric intake (based on the results of Protocol 1) with C7 for 6 months, undergo full evaluation and discontinuation of treatment at a 6 month visit, and return for an off-treatment follow up visit 3 months after C7 oil discon-tinuation, for total duration of participation of 9 months. Subjects will undergo treatment initiation on a 24-hour inpatient basis. During that 24-hr inpatient treatment initiation, subjects will have continuous eeG both to monitor for real-time seizure activity (for safety) and to determine eeG changes (secondary outcome) before, during, and after treatment initiation. Subjects will undergo clinical evaluation, comprehensive blood work, ataxia scale rating, eeG, and neuropsychological testing at baseline, 6 months, and 9 months.