GLUT1 DEFICIENCY: A MILD PHENOTYPE IN A 4 YEARS OLD FEMALE WITH EARLY ONSET ABSENCES AND ATAXIA

Introduction: Glucose (GLUT1) transporter 1 deficiency (OMIM 606777) is a polymorphic syndrome including an epileptic encephalopathy, early onset absences, complex movement disorders and developmental delay. Case report: We present the case of a 4 year old female with episodes of recurrent staring since the age of 3 months and fluctuating ataxic gait when awakening since the age of 2 years and 6 months. Symptoms were exacerbated at awakening and with fasting. Psychomotor development was only mildly impaired. Electroencephalogram evidenced diffuse epileptiform discharges with the prominent involvement of the anterior regions. Seizures have been well controlled with valproic acid. Brain MRI was negative. Lumbar puncture showed a CSF/blood glucose ratio of 0,28.Molecular investigation on SLC2A1 gene revelaed a heterozygosis for the mutation c.274 C>T (p.Arg92Trp). Discussion: GLUT1 deficiency have an expanding phenotype. Our experience evidences that the pattern of GLUT 1 deficiency includes different ranges of clinical severity. This is probably due to differences in the functional impairment of the transporter.