ESPE Abstracts

Background: Monocarboxylate transporter 8 (MCT8) is a specific transporter of triiodothyronine (T3). MCT8 gene mutations cause a rare X-linked disorder known as Allan–Herndon–Dudley syndrome, characterized by thyroid dysfunction (high T3, low T4, and normal/high TSH) and psychomotor retardation.Case report: A 4-year- and 9-month-old boy, who was already having L-T4 treatment fo...