Seizures, ataxia, developmental delay and the general paediatrician: Glucose transporter 1 deficiency syndrome

Abstract

Aim Glucose transporter 1 deficiency syndrome (GLUT1‐DS) is an important condition for the general paediatrician’s differential armamentarium. We describe a case series of eight patients in order to raise awareness of this treatable neurometabolic condition. The diagnosis of GLUT1‐DS is suggested by a decreased absolute cerebrospinal fluid (CSF) glucose value (<2.2 mmol/L) or lowered CSF: plasma glucose ratio (<0.4). Methods This is a review of eight Queensland patients with GLUT1‐DS. The clinical presentation, clinical course, laboratory investigations and treatment outcomes are discussed. Results The clinical features noted in our patient cohort include combinations of ataxia, developmental delay and a severe seizure disorder that is refractory to anticonvulsant medications. Seizures are the most common clinical manifestation and may be exacerbated by phenobarbitone. The paired CSF: plasma glucose results ranged from 0.2 to 0.39 (normal <0.6) with an average of 0.33. 3‐O‐Methyl‐D‐Glucose uptake and GLUT1 Genotyping analysis have been performed on five patients thus far. Rapid and impressive seizure control was observed in 100% of our patients once the ketogenic diet was instituted, with half of the cohort being able to wean completely from anticonvulsants. Conclusion Children presenting with a clinical phenotype consisting of a refractory seizure disorder, ataxia and developmental delay should prompt the consideration of Glucose transporter 1 deficiency syndrome. While the diagnostic test of lumbar puncture is an invasive manoeuvre, the diagnosis provides a viable treatment option, the ketogenic diet. GLUT1‐DS displays clinical heterogeneity, but the value of early diagnosis and treatment is demonstrated by our patient cohort.