Atypical Presentation of the GLUT-1 Deficiency Syndrome with Cataract and Normal Glucose Concentration in Cerebrospinal Fluid

Abstract

Background: The SLC2A1 gene on chromosome 1 encodes a glucose transporter in the blood-brain barrier. A defect of this gene is responsible for the glucose transporter 1 (GLUT-1) deficiency syndrome, a metabolic disease which leads to an undersupply of glucose for the brain. Main symptoms are infantile-onset seizures refractory to anticonvulsant medications, an acquired microcephaly, and developmental delay and movement disorders. Other than the mentioned diseases, there is a rare form of hereditary stomatocytosis, called stomatin-deficient cryohydrocytosis, caused by a mutation in the same gene as the mutation of the GLUT-1 deficiency syndrome. The patients show anemia, a cataract, as well as neurological symptoms such as epilepsy, developmental delay, and movement disorders. In our case report, we present a new mutation of the SLC2A1 gene which includes symptoms of both clinical pictures in the phenotypical spectrum.