What is Glut- Deficiency Syndrome (Glut-1 DS)
Glucose transporter type 1 deficiency syndrome (Glut1-DS) is characterized by infantile seizures refractory to anticonvulsants, followed by deceleration of head growth, delays in mental and motor development, spasticity, ataxia, dysarthria, opsoclonus, and other paroxysmal neurologic phenomena, often occurring prior to meals. Affected infants appear normal at birth following an uneventful pregnancy and delivery. Birth weight and Apgar scores are normal. Seizures usually begin between age one and four months. Apneic episodes and abnormal episodic eye movements simulating opsoclonus may precede the onset of seizures by several months. Five seizure types occur: generalized tonic or clonic, myoclonic, atypical absence, atonic, and unclassified. The frequency of seizures varies among affected individuals. Varying degrees of cognitive impairment, ranging from learning disabilities to severe mental retardation, are characteristic.
The diagnosis of Glut1-DS is established in neurologically impaired individuals with 1) reduced cerebrospinal fluid (CSF) glucose concentration (hypoglychorrhachia) 2) low ratio of CSF glucose concentration to blood glucose concentration. Molecular genetic testing is available on a clinical basis.