Sammanfattning
BACKGROUND In conditions with impaired sensitivity to thyroid hormone, reduced effect of thyroid hormone is attributable to
various defects. The purpose of this article is to give an overview of these conditions, as well as to provide updated knowledge
on impaired sensitivity to thyroid hormone, also known as thyroid hormone resistance, with mutations in thyroid hormone
receptor ß (TRß).
MATERIAL AND METHOD This article is based on a selection of English-language articles, and Norwegian original and review
articles found in PubMed, and the authors’ own experiences with this patient group.
RESULTS Thyroid hormone resistance has long been a recognised cause of the reduced effect of thyroid hormone. Several other
conditions that involve impaired sensitivity to thyroid hormone have been described in recent decades, and mutations have been
identified in genes that code for thyroid hormone receptor a (TRa), a cell membrane transporter, as well as in the deiodinases that
metabolise thyroxine (T4) to the bioactive form triiodothyronine (T3). The conditions vary in terms of their clinical picture and
biochemical profile.
INTERPRETATION Based on clinical and biochemical findings, thyroid hormone resistance may be erroneously interpreted as
hyperthyroidism. In patients with thyroid hormone resistance, the condition may be exacerbated if it is treated as
hyperthyroidism. It is therefore essential to recognise the conditions and their differential diagnoses.