First report of glucose transporter 1 deficiency syndrome in Korea with a novel splice site mutation

Glucose transporter type 1 deficiency syndrome (Glut-1DS) is caused by autosomal dominant haplodeficiency or autosomal recessive with homozygous mutation of the glucose transporter 1 (SLC2A1) gene and is characterized by severe seizures, developmental delay, ataxia and acquired microcephaly. We describe the first known Korean patient with glucose transporter 1 deficiency syndrome, who had a novel mutation in the splice site. The patient began having intractable seizures at 4days of age that initially presented as eye blinking and apnea, evolving into generalized tonic seizures. A lumbar puncture revealed low glucose concentration in the cerebrospinal fluid (CSF) in the setting of normoglycemia (blood glucose, 106mg/dl; CSF glucose 21mg/dl, and CSF to blood glucose ratio 0.20). The results of a 3-O-methylglucose uptake study in erythrocytes (RBC) revealed that glucose uptake reduced to 48% of his parents in the patient. The patient responded to a ketogenic diet that was initiated at 4months of age and currently is on the modified Atkins diet (MAD) without seizures. He does not require antiepileptic medication. We diagnosed the first Glut-1 patient in Korea with a novel splice site mutation on the basis of clinical features, deficient glucose uptake and a mutation in the SLC2A1 gene.