Misdiagnosis of Graves’ and RAI Treatment in Patient with THRB Gene Mutation

The article discusses a case of a 35-year-old female patient who was misdiagnosed with Graves' disease due to elevated T4 and T3 levels with normal TSH, leading to unnecessary radioactive iodine (RAI) treatment. Genetic testing revealed a mutation in the THRB gene, specifically a c.715T>A (pTrp239Arg) variant, which is associated with resistance to thyroid hormone (RTH). This condition can mimic hyperthyroidism, complicating diagnosis and treatment. The case highlights the importance of thorough evaluation, including genetic testing and correlation of thyroid function tests with imaging, to avoid misdiagnosis and inappropriate treatment. It also emphasizes the challenges in managing thyroid hormone levels in RTH patients post-ablation.