A type of central congenital hypothyroidism with characteristics of low levels of thyroid hormones due to insufficient release of thyroid-stimulating hormone (TSH) caused by pituitary resistance to thyrotropin-releasing hormone (TRH). It may or may not be observed from birth. The clinical manifestations are often subtle, probably as a result of trans-placental passage of some maternal thyroid hormone or due to the fact that many infants have some thyroid production of their own. More specific symptoms and signs often do not develop until several months of age. Common clinical features and signs include decreased activity and increased sleep, feeding difficulty and constipation, prolonged jaundice. Slow linear growth and developmental delay are usually apparent by 4-6 months of age. Caused by mutations in the TRH receptor gene (TRHR; 8q23). [from
SNOMEDCT_US]