GLUT-1 deficiency presenting with seizures and reversible leukoencephalopathy on MRI imaging

Glucose transporter type 1 (GLUT1) deficiency syndrome is a well recognised genetic neurometabolic disorder typically presenting with progressive encephalopathy, acquired microcephaly and drug-resistant epilepsy. Imaging is normal in the majority. Here we describe a 5-month-old boy who presented with motor delay, myoclonic jerks and tonic-clonic seizures. His MRI brain scan revealed confluent symmetrical T2 hyperintense signal abnormality in both anterior frontal lobes and delayed myelination. Neurometabolic screen revealed low CSF glucose and lactate levels. A pathogenic de novo heterozygous mutation in SLC2A1 (c.275+1G > A) confirmed the diagnosis of GLUT1 deficiency. Ketogenic diet resulted in a dramatic termination of his seizures at 72 h. At 15 months, he continued to be seizure free with marked developmental catch up. Repeat imaging revealed a significant resolution of the previously seen changes. This case suggests that GLUT1 deficiency should be considered in the differential diagnosis of infants with suspected genetic leukoencephalopathies with important treatment implications.