Endocrine Abstracts

Thyroid hormone resistance is an inherited disorder with an incidence of about 1 in 50 000 live births. It is characterised by reduced response to the hormone at tissue level. Though many cases have been reported and there is growing awareness of the rare condition, there are reports of many patients being wrongly diagnosed as Graves disease and therefore undergoing various inappropriate treatments. We report the case of a 7-year-old boy who was referred to our service with abnormal thyroid function tests.

He was referred to our service by the community paediatric team where he had presented with a history of behaviour problems, learning difficulties and poor concentration.

He was born preterm at 32 weeks and required a brief stay in the neonatal unit. His weight was initially on the 50th centile but had drifted gradually to the 3rd centile. There was a family history of thyroidectomy for hyperthyroidism. His physical examination was normal with no features of hyper or hypothyroidism. His thyroid function test showed high T4 levels (26, 36 and 39 pmol/l) in the presence of normal TSH (1.2, 0.96 and 1.3 mU/l) respectively. His thyroid peroxidise antibodies and antithyroid antibodies were negative. Genetic testing showed a THRβ mutation. Parental screening is currently being undertaken. The community paediatric team and school have been involved to support his behaviour and learning difficulties. He is currently stable on no medication.

Triiodothyroacetic acid, dextro-thyroxine, bromocriptine, corticosteroids, β blockers, and antithyroid drugs are some of the medications that have been used to manage symptomatic patients with varying efficacy, side effects and limitations.