Abstract
Resistance to thyroid hormone (RTH) is an extremely rare dominantly inherited condition of impaired tissue responsiveness to thyroid hormone (TH). Most patients with RTH have mutations in the gene that encodes the β isoform of the receptor of thyroid hormone (THR-β gene). Mutant receptors are unable to activate or repress target genes. The majority of them are asymptomatic or rarely have hypo- or hyperthyroidism. RTH is suspected by the finding of persistent elevation of serum levels of free T3 (FT3) and free T4 (FT4) and nonsuppressed TSH. We present two cases of RTH diagnosed after total thyroidectomy. The first patient was initially diagnosed with primary hyperthyroidism due to toxic multinodular goiter. The second patient had undergone thyroidectomy for multinodular goiter 16 years before diagnosis of RTH. After thyroidectomy, although on relatively high doses of levothyroxine, both of them presented with the laboratory findings of RTH. Genetic analysis revealed RTH.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
