Efficacy and safety evaluation of ketogenic diet therapy in patients with glucose transporter type 1 deficiency syndrome.

Objective: Glucose transporter type 1 deficiency syndrome (GLUT1-DS) presents with diverse clinical manifestations and varying degrees of severity. This study aims to investigate the clinical characteristics of patients with GLUT1-DS and to evaluate the efficacy and safety of ketogenic diet (KD). Methods: Clinical data were retrospectively collected from 56 patients with GLUT1-DS treated at Shanghai Deji Hospital between March 2015 and May 2024. We analyzed the initial presentations, primary clinical manifestations, cerebrospinal fluid (CSF) characteristics, and genetic testing results, as well as the efficacy and safety of ketogenic diet therapy (KDT). Results: The median age of onset was 6.0 months, and diagnosis was confirmed at a median age of 32.5 months. Epilepsy was the initial symptom in 69.6% of cases, followed by movement disorders (17.9%) and developmental delay (12.5%). CSF analysis revealed a mean glucose level of 1.80 ± 0.33 mmol/L and a CSF-to-blood glucose ratio of 0.39 ± 0.07. Genetic testing confirmed Conclusion: Our findings support the effectiveness and acceptable short-term safety of KDT for patients with GLUT1-DS. KD was associated with improved seizure control, motor function, and caregiver-reported gains in language and cognition. These findings support current recommendations favoring early diagnosis and timely initiation of treatment.