A case of thyroid hormone resistance

Resistance to thyroid hormone is a rare syndrome that generally shows autosomal dominant inheritance and characterized by a reduced responsiveness of target tissues to thyroid hormone action. Diagnosis is based on persistent elevations of serum free T4 and often T3 levels in the absence of serum thyrotropin suppression and confirmation in most cases is by way of genetic testing. Patients with thyroid hormone resistance usually become euthyroid, but in rare cases, symptoms and findings of thyrotoxicosis or hypothyroidism may appear. Herein, we report a 33-year-old female case with late diagnosis.