Congenital hypothyroidism is the most frequent inborn endocrine disorder and the most frequent disease diagnosed by nation-wide newborn screeening. 80-85% of permanent cases is caused by a defective thyroid development - thyroid dysgenesis. Remaining cases are caused by defects of thyroid hormone biosynthesis - dyshormonogenesis.
Early and adequate substitution treatment together with a good family compliance are the main factors playing role in psychomotor, mental and somatic development of the majority of children with congenital hypothyroidism.