Abstract
Mutations of the thyroid hormone cell-transporter gene, monocarboxylate
transporter 8, or MCT8, cause an X-linked syndrome characterized by altered thyroid
hormone concentrations in serum, profound neuromotor impairment, and cognitive
deficits. This chapter describes the clinical features of the syndrome and analyzes the
mechanisms of disease from studies of MCT8 deficiency in mice. The final section of
the chapter describes the available treatments and experimental therapies.