Thyroid Hormone Resistance Syndromes

Syndromes with impaired sensitivity to thyroid hormone (TH) include three types of resistance to thyroid hormone (RTH) syndromes (RTHβ, RTHα, and nonTR-RTH) and also include patients with defects in TH transport into cells (thyroid hormone cell membrane transport defect, THCMTD) and defects in TH metabolism (thyroid hormone metabolism defect, THMD). The overall goal of this chapter is to discuss the treatment options for patients with various syndromes of impaired sensitivity to TH. These are rare conditions with little or no evidence-based information for the “best” treatment of patients. The first step toward treatment of all of these syndromes is making an accurate diagnosis based on a combination of the clinical presentation and laboratory tests that ultimately requires genetic confirmation. Recognizing the etiology leads to a more logical approach to treatment.