Glucose transporter type 1 (GLUT1 or SLC2A1) is a glucose transporter responsible for constitutive or basal glucose uptake. GLUT1 has a very broad substrate specificity such as pentoses and he, Xenopus/Amphibian,oses. GLUT1 is e, Xenopus/Amphibian,pressed at variable levels in many human tissues. Defects in GLUT1 are the cause of autosomal dominant GLUT1 deficiency syndrome, a blood-brain barrier glucose transport defect characterized by infantile seizures and delayed development. Defects in GLUT1 are also the cause of dystonia type 18 (DYT18), an e, Xenopus/Amphibian,ercise-induced paro, Xenopus/Amphibian,ysmal dystonia/dyskinesia (muscle contraction disorders).