Case Diagnosis: A 4-year and 3-month-old female with glucose transporter type 1 deficiency syndrome showed significant functional improvement on a ketogenic diet.
Case Description or Program Description: A 4-year, 3-month-old female with a history of ataxia, dystonia, epilepsy refractory to anti-epileptics, and presumed cerebral palsy with developmental delay presented to clinic with regression of milestones. Genetic workup was completed and revealed glucose transporter type 1 deficiency syndrome (GLUT1DS) with pathogenic variant of SLC2A1. She was started on a 3:1 ketogenic diet with significant functional improvement.
Assessment/Results: Within 24 hours after diet initiation, mother reported increase in speech frequency. Within a week, she had decreased head jerking and 2-3 new words. Speech therapy noted more frequent repetitions and more independent attempts to produce short phrases. After 2 weeks, physical therapists noted less ataxia and less lateral deviations in gait. In 3 weeks, she independently stood from the floor, maintaining balance for 5 seconds for which she previously required minimum assist. In occupational therapy, she progressed from maximum assist with loop scissors to independently using loop scissors 4 months later.
She remained seizure free 6 months later with good weight gain, advancing from the 16th to 40th percentile in weight in 3 weeks and to the 68th percentile by 5 months.
Discussion (relevance): In the setting of regression of milestones, pursuing etiology is important for appropriate targeted treatment. While literature has shown that patients with GLUT1DS on a ketogenic diet have significant reduction in seizures, data on functional improvement in these patients on a ketogenic diet is limited.
Conclusions: This case demonstrates functional improvement across cognitive, fine motor, and gross motor development in a 4-year, 3-month-old female with GLUT1DS on a ketogenic diet. It highlights the importance of pursuing additional etiology in the setting of regression of milestones for meaningful treatment and recovery of function.