Thyroid hormone resistance (THR) is a rare syndrome of reduced end organ 
sensitivity. Patients with THR have elevated serum free thyroxine (FT4), free 
triiodothyronine (FT3), but normal or slightly elevated serum thyrotropin 
values. The characteristic clinical feature is goitre without symptoms and 
metabolic consequences of thyroid hormone excess. THR can be classified on the 
basis of tissue resistance into pituitary, peripheral or generalised (both 
pituitary and peripheral) types. Mutations in the TRbeta gene, cell membrane 
transporter and genes controlling intracellular metabolism of thyroid hormone 
have been implicated. THR is differentiated from thyroid stimulating hormone 
(TSH) secreting pituitary adenoma by history of THR in the family. No specific 
treatment is often required for THR; patients with features of hypo- or 
hyperthyroidism are appropriately treated with levo-triiodothyronine (L-T3), 
levo-thyroxine (L-T4), dextro-thyroxine(D-T4) or 3,3,5 triiodo-thyroacetic acid 
(TRIAC). The diagnosis helps in appropriate genetic counselling of the family.