Resistance to thyroid hormone (RTH), a syndrome characterized by variable tissue hyposensitivity to thyroid hormone, is linked to mutations in the thyroid hormone receptor-beta (TR beta) gene.
Generalized resistance to thyroid hormone (GRTH) is a disorder of thyroid hormone action which has been linked to the beta thyroid hormone receptor (TR beta) gene.
Resistance to thyroid hormone (RTH) is a dominantly inherited syndrome characterized by hyposensitivity to thyroid hormone caused by mutations in the thyroid hormone receptor-beta (TR beta) gene.
Resistance to thyroid hormone (RTH) is an inherited defect manifesting as variable tissue hyporesponsiveness to thyroid hormone, usually caused by mutations in the thyroid hormone receptor beta (TR beta) gene.
A 44-year-old Japanese woman with RTH, which was confirmed by the presence of a P453A mutation in the thyroid hormone receptor β (TRβ) gene, showed a slight elevation of the basal levels of thyroid hormones, which indicated that her pituitary RTH was mild.
All subjects fulfilling the criteria of RTH (6 of family F94 and one of family F27) had the same point mutation in the T3-binding domain on one of the two alleles of the TR beta gene.
Defects in TRβ lead to RTH (resistance to thyroid hormone) β, a syndrome characterized by high levels of thyroid hormone and non-suppressed TSH (thyroid-stimulating hormone).
Here, we hypothesized that additional pathogenic mutations in TRβ are likely to exist in human population and analysed clinical cases with suspected RTH.
In particular, the application of 3,3',5-triiodothyroacetic acid (Triac) in RTH due to defective TRβ and the role of 3,5-diiodothyropropionic acid (DITPA), 3,3',5,5'-tetraiodothyroacetic acid (Tetrac) and Triac in MCT8 deficiency will be highlighted.
Mice with a knock-in mutation in the TRβ gene spontaneously develop TSHomas, although as yet no patient has been reported to have both a TSHoma and RTHβ.
Mice with mutations in the thyroid hormone receptor beta (TRβ) gene that cannot bind steroid receptor coactivator 1 (SRC-1) and Src-1(-/-) mice both have phenotypes similar to that of RTH.
Sequence analysis of the TR beta gene from a patient with the syndrome of resistance to thyroid hormone revealed a novel missense mutation in exon 9, changing thymidine in position 1123 to cytosine.
Seventeen patients presented mutations in TRβ (RTHβ); six were non-TR-RTH, three had a diagnosis of FDH with a mutation in ALB, and four were diagnosed with TPA.
Since similar mutations have been identified in tri-iodothyronine (T3) receptor (TR) beta gene in GRTH and PRTH, and since considerable overlap has been seen in the clinical manifestations in patients with GRTH and PRTH, two subtypes of RTH are now considered to be a continuous spectrum with the same genetic defect.
The aim of the study was to describe the clinical, biochemical, and genetic features of a sample of Mediterranean patients with RTH (resistance to thyroid hormone) due to mutations in TRβ (thyroid hormone receptor beta) referred to our institution during the last 15 years.