Adequate delivery of thyroid hormones to the brain is crucial for normal neurological development. MCT8 and OATP1C1, two solute carrier (SLC) transporters, mediate the passage of thyroid hormones across the blood-brain barrier and into the central nervous system. Mutations in MCT8 result in Allan-Herndon-Dudley syndrome (AHDS), an X-linked birth defect characterized by neurodevelopmental impairments and peripheral hyperthyroidism, whereas OATP1C1 deficiency is linked to brain hypometabolism and ...