congenital hypothyroidism, non-goitrous, type 1

(redirected from TSH resistance)

congenital hypothyroidism, non-goitrous, type 1

A non-autoimmune condition (OMIM:275200) characterised by resistance to TSH, leading to increased plasma TSH and reduced thyroid hormone. CHNG1 presents with a range of severity: most patients are euthyroid and asymptomatic, with a thyroid gland of normal size, while a subset of patients develop hypothyroidism and have a hypoplastic thyroid gland.

Molecular pathology
Caused by defects of TSHR, which encodes the protein receptor for thyrothropin and thyrostimulin.
References in periodicals archive ?
He also talked about sub clinical hypothyroidism, NTI recovery phase, TSH resistance, adrenal insufficiency besides use of steroids and dopamine.
Hormone resistances, usually PTH and/or TSH resistance, have been detected in about 60-70% of acrodysostosis patients with a PRKAR1A mutation and in 10-20% of cases with PDE4D mutations.
TSH resistance is usually characterized by mildly elevated TSH levels with a normal or low-normal free thyroxine (T4) level.
TSH resistance could be a first manifestation of iPPSD, especially if referred from the neonatal screening program for congenital hypothyroidism (68,69).
Thus, increased TSH (6.02 mIU/L) with normal f[T.sub.3] and f[T.sub.4] levels in subsequent measurements suggested TSH resistance. Elevated PTH levels (138.1 pg/mL) were still evident, while serum calcium, phosphorous, and ALP concentrations were normal.
While PTH resistance associated later with TSH resistance was apparent in our patient, resistance to gonadotropins or GHRH was not detected.
TSH resistance becomes clinically apparent during the adolescence period (1).
Based on our results, one should take into account two different periods each with its related signs, namely, round face, rapid weight gain, subclinical hypothyroidism, and subcutaneous calcifications in toddlers, and moderate mental retardation, brachydactyly, afebrile seizures (hypocalcemia), short stature, and TSH resistance in older children.