FT4 estimation by equilibrium dialysis excluded analytical interference, and molecular analysis for the thyroid hormone receptor β gene associated with thyroid hormone resistancewas negative.
Individuals with RTH due to TRbeta gene mutations have an increased likelihood of AITD compared to unaffected relatives, but the prevalence of thyroid autoantibodies with advancing age is not affected by genotype.
Resistance to thyroid hormone (RTH), a dominantly inherited disorder usually associated with mutations in thyroid hormone receptor beta (THRB), is characterized by elevated levels of circulating thyroid hormones (including thyroxine), failure of feedback suppression of thyrotropin, and variable tissue refractoriness to thyroid hormone action.
Interestingly, molecular genetic testing showed that, whereas the elder sister is affected by PS, the younger sister has both PS (due to compound heterozygous SLC26A4 mutations) and RTH (due to a novel de novo heterozygous THRB mutation).
Resistance to thyroid hormone (RTH) is a dominantly inherited syndrome of reduced tissue responsiveness to thyroid hormone usually due to mutations located in the ligand-binding domain and adjacent hinge region of the thyroid hormone receptor beta (TRbeta).
Of the 141 families with RTH investigated by us, 21 (15%) had no TRbeta gene mutations detectable by sequencing from genomic DNA (gDNA) or cDNA (non-TR RTH).
Mutational analysis of the thyroid hormone receptor beta gene allows definitive diagnosis of RTH, potentially avoiding the need for protracted and expensive pituitary function testing and imaging.
Tissue responses to thyroid hormone in a kindred with resistance to thyroid hormone harboring a commonly occurring mutation in the thyroid hormone receptor beta gene (P453T).