Etiology
- Thyroid gland malformation:
- Agenesis: Absent thyroid gland
- Dysgenesis: Ectopic (e.g., sublingual) or incorrectly formed (e.g., hemigland) thyroid
- Dyshormonogenesis:
- 15 known defects of thyroxine (T4) synthesis, including those in iodide transport and iodide organification
- Transient hypothyroidism:
- Maternal ingestion of antithyroid drugs
- Transplacental transfer of maternal antithyroid antibodies (can be transient or permanent damage)
- Exposure to high levels of iodine povidone, betadine in neonatal period
