GLUT1 deficiency syndrome type 1
GLUT1 deficiency syndrome type 1A neurologic disorder (OMIM:606777) with a wide phenotypic variability. The “classic” phenotype is severe and comprises infantile-onset epileptic encephalopathy, delayed development, acquired microcephaly, motor incoordination and spasticity. Seizures, usually characterised by apnoeic episodes, staring spells and episodic eye movements, begin shortly after birth; other findings include intermittent ataxia, confusion, lethargy, sleep disturbance and headache. Cognitive impairment is variable, ranging from learning disabilities to severe mental retardation.
Defects of SLC2A1, which encodes a facilitative glucose transporter with very broad substrate specificity, cause GLUT1 deficiency syndrome type 1.