患儿1，男，4岁，因语言发育迟缓就诊，甲状腺功能显示游离三碘甲状腺原氨酸、游离甲状腺素持续升高，促甲状腺激素正常或升高，基因检测发现THRB基因c.1373T>C（p.Val458Ala）新生杂合突变，诊断为甲状腺激素抵抗综合征（resistance to thyroid hormone syndrome, RTH），未予特殊药物治疗，定期随访观察。患儿2，男，2岁，新生儿筛查发现促甲状腺激素升高，甲状腺功能异常持续1年10个月，伴生长迟缓及心动过速，基因检测提示THRB基因c.959G>A（p.Arg320His）新生杂合突变，诊断为垂体型RTH，予普萘洛尔控制心率。RTH临床表现异质性大，易误诊漏诊。对于不明原因甲状腺功能异常伴发育障碍的患儿，需警惕本病可能，早期THRB基因检测有助于精准诊断与治疗决策。

Patient 1, a 4-year-old boy, presented with delayed language development. Persistently elevated free triiodothyronine (FT3) and free thyroxine (FT4) were found, with normal or elevated thyroid-stimulating hormone (TSH). A de novo heterozygous mutation in the THRB gene (c.1373T>C, p.Val458Ala) was identified, and resistance to thyroid hormone syndrome (RTH) was diagnosed. No specific medication was administered, and regular follow-up was arranged. Patient 2, a 2-year-old boy, had elevated TSH detected on neonatal screening. Thyroid dysfunction persisted for 1 year and 10 months and was accompanied by growth delay and tachycardia. Genetic testing revealed a de novo heterozygous mutation in the THRB gene (c.959G>A, p.Arg320His), and pituitary-type RTH was diagnosed. Propranolol was administered for heart rate control. RTH shows marked clinical heterogeneity and is prone to misdiagnosis or missed diagnosis. For children with unexplained thyroid dysfunction and developmental disorders, early THRB gene testing helps achieve precise diagnosis and guide treatment decisions.