Resistance to thyroid hormones (RTH) is a rare disease with prevalence 1 : 40 000-50 000. About 85% of cases are caused by mutation of thyroid hormone receptor gene β (TRβ) and in 15% of cases the mutation cannot be detected (nonTR-RTH).
Elevated thyroid hormone and non-suppressed TSH in the blood, goitre and variable other clinical symptoms are typical for the disease.