Tyreoideahormonresponserhet

Tyreoideahormonresponserhet, also known as thyroid hormone resistance, is a rare endocrine disorder characterized by impaired responsiveness of target tissues to endogenous thyroid hormones. The condition results from inherited or sporadic mutations in the thyroid hormone receptor alpha (THRA) or beta (THRB) genes, leading to reduced affinity or altered signaling downstream of the receptor complex. Clinical presentation varies widely; some individuals exhibit hyperthyroidism‑like symptoms such as tachycardia and heat intolerance, while others present with hypothyroidism‑like features including fatigue and weight gain. Laboratory investigations typically reveal elevated serum triiodothyronine (T3) and thyroxine (T4) concentrations accompanied by a inappropriately normal or only mildly increased thyroid‑stimulating hormone (TSH). Molecular genetic analysis confirms pathogenic variants and assists in distinguishing type 1 versus type 2 resistance, which differ in receptor subtype involvement and associated phenotypes.

Management is predominantly supportive, tailored to the patient’s symptom profile. Beta‑blockers may alleviate adrenergic manifestations, whereas low‑dose thyroid hormone replacement can be used cautiously in patients manifesting peripheral hypothyroidism. In type 2 resistance, careful titration of levothyroxine is necessary to avoid worsening neurodevelopmental or psychiatric symptoms. Regular monitoring of thyroid function tests, growth parameters in children, and assessment of quality of life are essential components of care. Recent advances in understanding receptor isoform function and gene‑editing potential offer future therapeutic avenues, though no definitive curative treatment currently exists.