Approximately 10% of patients with congenital hypothyroidism harbor inborn errors of metabolism in one of the steps for thyroid hormone synthesis in thyrocytes (Vono-Toniolo et al., 2005). Dyshormonogenesis can be caused by recessive defects at any of the steps required for normal thyroid hormone synthesis. In untreated patients thyroid dyshormonogenesis is typically associated with goitrous enlargement of the thyroid secondary to long-term thyrotropin (TSH; see 188540) stimulation.

Reference
OMIM: Thyroid dyshormonogenesis