(English) Hyperthyrotropinemia without Hypothyroidism – Report on a Family Presenting Receptor Insensitivity to Thyrotropin?

Higher Medical Institute-Plovdiv

Department of Pediatrics

*Department of General and Clinical Pathology

 

Abstract:

Mass screening examination of neonates for congenital hypothyroidism contributes greatly to detect uncommon parrerns of deviation in the level of thyroid (T3 and T4) and thyrotropic (TSH) hor¬mones. Hyperthyrotropinemia at normal T3 and T4 concentrations is not infrequently found in neo¬nates, usually interpreted as an expression of sub¬clinical hypothyroidism attributable to slight degree enzymatic defects, or thyroid gland ectopia. In the last five years, reports have been published on re¬sistance to TSH, becoming manifest with euthyMass screening examination of neonates for congenital hypothyroidism contributes greatly to detect uncommon parrerns of deviation in the level of thyroid (T3 and T4) and thyrotropic (TSH) hor¬mones. Hyperthyrotropinemia at normal T3 and T4 concentrations is not infrequently found in neo¬nates, usually interpreted as an expression of sub¬clinical hypothyroidism attributable to slight degree enzymatic defects, or thyroid gland ectopia. In the last five years, reports have been published on re¬sistance to TSH, becoming manifest with roid hyperthyrotropinemia.

This is a report on the first observation of euthyroid hyperthyrotropinemia in this country, documented in seven members from two genrations in a single family. In one of the children there are ocular anomalies, and in four – idiopathic arterial calcinosis. The results of neonatal screen¬ing for hypothyroidism among children with el¬evated TSH levels at normal FT3 and FT4 prompted the detection of anomalies. It is of interest to note that hyperthyrotropinemia persists in rather advanved age: analogical changes are likewise dis¬covered in two members of the preceding genera¬tion.

The assumption is warranted that it is a matter of TSH resistance due to receptor insensi-tivity. The latter may be related to mutation of the gene responsible for regulation of TSH receptors, and conditions hyperthyrotropinemia development in case of normal location and function of the thy¬roid gland.

 

Keywords: familial hyperthyrotro­pinemia, thyroid hormones, resistance to TSH