Congenital hypothyroidism.

Area of Science:

• Neonatology
• Endocrinology
• Genetics

Background:

• Congenital hypothyroidism (CH) is a present-at-birth thyroid hormone deficiency.
• Untreated CH leads to severe mental retardation, often without clear early symptoms.
• Screening programs have significantly reduced the impact of CH worldwide.

Purpose of the Study:

• To review advances in understanding fetal and neonatal thyroid physiology.
• To discuss molecular insights into thyroid gland development and function.
• To highlight current challenges in CH diagnosis and management.

Main Methods:

• Literature review of congenital hypothyroidism.
• Analysis of advances in molecular biology related to thyroid function.
• Discussion of diagnostic and screening challenges.

Main Results:

• Screening for CH has largely prevented mental retardation associated with the condition.
• Understanding of CH etiologies (permanent/transient, primary/secondary/peripheral) has advanced.
• Molecular biology has elucidated mechanisms of thyroid hormone action and inborn errors.

Conclusions:

• Despite progress, challenges remain, particularly for premature infants.
• Definitive diagnostic criteria and treatment guidelines are needed for specific neonate populations.
• Optimizing sensitive and cost-effective screening methodologies is an ongoing challenge.