Monocarboxylate transporter 8 (MCT8) is a thyroid hormone transporter, the gen e of which is located on the X chromosome. We tested whether mutations in MCT8 c ause severe psychomotor retardation and high serum triiod...Monocarboxylate transporter 8 (MCT8) is a thyroid hormone transporter, the gen e of which is located on the X chromosome. We tested whether mutations in MCT8 c ause severe psychomotor retardation and high serum triiodothyronine (T3) concent rations in five unrelated young boys. The coding sequence of MCT8 was analysed b y PCR and direct sequencing of its six exons. In two patients,gene deletions of 2·4 kb and 24 kb were recorded and in three patients missense mutations Ala150 Val, Arg171 stop, and Leu397Pro were identified. We suggest that this novel syndrome of X linked psychomotor retardation is due to a defect in T3 entry i nto neurons through MCT8, resulting in impaired T3 action and metabolism.展开更多
文摘Monocarboxylate transporter 8 (MCT8) is a thyroid hormone transporter, the gen e of which is located on the X chromosome. We tested whether mutations in MCT8 c ause severe psychomotor retardation and high serum triiodothyronine (T3) concent rations in five unrelated young boys. The coding sequence of MCT8 was analysed b y PCR and direct sequencing of its six exons. In two patients,gene deletions of 2·4 kb and 24 kb were recorded and in three patients missense mutations Ala150 Val, Arg171 stop, and Leu397Pro were identified. We suggest that this novel syndrome of X linked psychomotor retardation is due to a defect in T3 entry i nto neurons through MCT8, resulting in impaired T3 action and metabolism.
