Congenital and juvenile nongoitrous hypothyroidism

Nongoitrous congenital and juvenile hypothyroidism is a rather common endocrine disorder occurring in approximately 1:5000–1:8500 normal children. The most frequent cause is thyroid ectopy (‘cryptothyroidism’) followed by atrophy of unknown cause and chronic atrophic thyroiditis. The clinical symptomatology is defined by disturbances of general metabolism and, most typically, by retarded somatic and mental development, leading in its extreme form when untreated, to so-called cretinism. The i treatment with thyroid hormone replacement has to be administered as early as possible. The prognosis for mental development depends on the brain damage present when treatment was started. Screening of thyroid function in neonates is the most reasonable method to make an early diagnosis.