title: Congenital hypothyroidism: recent advances.
abstract: OBJECTIVE
  This review summarizes significant recent advances in the epidemiology, pathophysiology, and treatment of congenital hypothyroidism.
  
  
  RESULTS
  The apparent incidence of congenital hypothyroidism has more than doubled in recent years because of several factors, including more inclusive diagnostic criteria, shifting demographics, and increasing survival of preterm infants. The greatest increase has occurred in mildly affected patients, many of whom have a eutopic thyroid gland. Congenital hypothyroidism may be transient or persistent, but the natural history cannot be predicted by severity at diagnosis. In premature infants, who are especially vulnerable to hypothyroidism, the rise in thyroid-stimulating hormone may be delayed and therefore detected only by routine follow-up screening. Recent studies of defects in thyroid hormone synthesis have focused on the role of mutations in the dual oxidase system and of a novel apical iodide transporter, anoctamin 1. Finally, emerging data suggest that exposure to excess thyroid hormone may be as harmful as hypothyroidism to long-term cognitive development.
  
  
  CONCLUSIONS
  Although newborn screening has virtually eradicated mental retardation due to congenital hypothyroidism in parts of the world, new information continues to accumulate and new questions to arise about the diagnosis, physiology, and optimal management of this disorder.
authors: Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors: Ari J
authors: AJ
authors: Wassner
authors: Rosalind S
authors: RS
authors: Brown
mesh_terms: D000328:Adult; D003409:Congenital Hypothyroidism / Q000175:diagnosis / Q000473:pathology / Q000628:therapy*; D005260:Female; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007234:Infant, Premature; D015997:Neonatal Screening; D011247:Pregnancy