THYROID HORMONE CELL-MEMBRANE TRANSPORTERS DEFECT: A NOVEL GENETIC SYNDROME OF THYROID HORMONE RESISTANCE

Many studies has confirmed the crucial role of thyroid hormone transporters for TH action in human target cells. The importance was better understood by observing the phenotype in patients harboring mutations of the monocarboxylate transporter 8 (MCT8) gene immediately linked to Allan Herndon-Dudley Syndrome (AHDS), in which severe neurological findings are associated with abnormal Thyroid hormone levels. The disease is X-chromossome linked, with males presenting a homogeneous neurological psychomotor phenotype and mental retardation associated with low serum T4 and elevated T3 levels. The mechanism of disease is still obscure and either the physiopathology as the existent therapeutic options need to be better studied.