[Impaired sensitivity to thyroid hormone].
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 β (TRβ).


METHODS
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 α (TRα), 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.


CONCLUSIONS
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.
Hormonlaboratoriet Haukeland universitetssykehus.
Silje Agnethe Stokke
SA
Kvistad
Medisinsk avdeling Haukeland universitetssykehus.
Paal
P
Methlie
Medisinsk avdeling Haukeland universitetssykehus og Klinisk institutt 2 Universitetet i Bergen.
Kristian
K
Løvås
Hormonlaboratoriet Haukeland universitetssykehus og Klinisk institutt 2 Universitetet i Bergen og KG Jebsen Senter for diabetesforskning Universitetet i Bergen.
Jørn V
JV
Sagen
D006801:Humans; D027501:Monocarboxylic Acid Transporters / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D037021:Thyroid Hormone Receptors alpha / Q000235:genetics / Q000378:metabolism; D037042:Thyroid Hormone Receptors beta / Q000235:genetics / Q000378:metabolism; D018382:Thyroid Hormone Resistance Syndrome / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism; D013963:Thyroid Hormones / Q000235:genetics / Q000378:metabolism
D027501:Monocarboxylic Acid Transporters; D037021:Thyroid Hormone Receptors alpha; D037042:Thyroid Hormone Receptors beta; D013963:Thyroid Hormones