MedGen

Resistance to thyroid-stimulating hormone (TSH; see 188540), a hallmark of congenital nongoitrous hypothyroidism, causes increased levels of plasma TSH and low levels of thyroid hormone. Only a subset of patients develop frank hypothyroidism; the remainder are euthyroid and asymptomatic (so-called compensated hypothyroidism) and are usually detected by neonatal screening programs (Paschke and Ludgate, 1997). Genetic Heterogeneity of Congenital Nongoitrous Hypothyroidism Also see CHNG2 (218700), caused by mutation in the PAX8 gene (167415) on chromosome 2q14; CHNG3 (609893), caused by mutation in the STRTS short tandem repeat (620900) on chromosome 15q26.1; CHNG4 (275100), caused by mutation in the TSHB gene (188540) on chromosome 1p13; CHNG5 (225250), caused by mutation in the NKX2-5 gene (600584) on chromosome 5q35; CHNG6 (614450), caused by mutation in the THRA gene (190120) on chromosome 17q21; CHNG7 (618573), caused by mutation in the TRHR gene (188545) on chromosome 8q24; CHNG8 (301033), caused by mutation in the TBL1X gene (300196) on chromosome Xp22; and CHNG9 (301035), caused by mutation in the IRS4 gene (300904) on chromosome Xq22. [from OMIM]

A rare hyperthyroidism characterized by mild to severe hyperthyroidism, presence of goiter, absence of features of autoimmunity, frequent relapses while on treatment and a positive family history. [from ORDO]

Some degree of stimulation of the thyroid gland by chorionic gonadotropin (see 118860) is common during early pregnancy. When serum chorionic gonadotropin concentrations are abnormally high, e.g., in women with molar pregnancies (231090), overt hyperthyroidism may ensue. The pathophysiologic mechanism appears to be promiscuous stimulation of the thyrotropin receptor by the excess chorionic gonadotropin. The explanation for this stimulation is the close structural relations between chorionic gonadotropin and thyrotropin and between their receptors (Grossmann et al., 1997). [from OMIM]