DEFICIENT TRANSPORT OF DEHYDROASCORBIC ACID IN THE GLUCOSE-TRANSPORTER PROTEIN SYNDROME

The glucose transporter protein syndrome (GTPS) is caused by defective transport of glucose across the blood-brain barrier via the glucose t ransporter GLUT1, resulting in hypoglycorrhachia, infantile seizures, and developmental delay. Recent reports indicated that GLUT1 is a mult ifunctional transporter. We investigated the transport of vitamin C in its oxidized form (dehydroascorbic acid) via GLUT1 into erythrocytes of 2 patients with GTPS, In both patients, uptake of oxidized vitamin C was 61% of the mothers' values. Our findings are consistent with rec ent observations that vitamin C is transported in its oxidized form vi a GLUT1. We speculate that impaired transport of this substrate and pe rhaps other substrates in GTPS might contribute to the pathophysiology of this condition.