New GLUT-1 mutation in a child with treatment-resistant epilepsy.

Mutations in the human glucose transporter type I (GLUT-1) gene may result in a phenotype of epilepsy, developmental delay, and movement abnormalities. We present a previously unreported mutation, c.1454 C>T (pPro485Leu) as a likely cause of intractable infantile-onset epilepsy and mild developmental delay in an 11-year-old girl. CSF:serum glucose ratio was 45%. She has had clinical improvement on a modified Atkins diet. Our patient helps further refine the phenotype of Glut-1 deficiency and reveals a new pathologic mutation.