Thyroid hormone resistance and its management

Abstract

The syndrome of impaired sensitivity to thyroid hormone, also known as syndrome of thyroid hormone resistance, is an inherited condition that occurs in 1 of 40,000 live births characterized by a reduced responsiveness of target tissues to thyroid hormone due to mutations on the thyroid hormone receptor. Patients can present with symptoms of hyperthyroidism or hypothyroidism. They usually have elevated thyroid hormones and a normal or elevated thyroid-stimulating hormone level. Due to their nonspecific symptomatic presentation, these patients can be misdiagnosed if the primary care physician is not familiar with the condition. This can result in frustration for the patient and sometimes unnecessary invasive treatment such as radioactive iodine ablation, as in the case presented herein.

Figure 1.

Sequence analysis of the thyroid hormone receptor beta (THRB) gene showing a heterozygous mutation C>A located in exon 10. The mutation results in a change of proline for threonine at amino acid position 453, P453T.