Nongoitrous Congenital Hypothyroidism 2 - CHNG2 (Mutations of PAX8/TTF-1/TTF2)
Thyroid dysgenesis; Thyroid agenesis; Thyroid hypoplasia; Thyroid ectopic; Hypothyroidism; Congenital due to thyroid dysgenesis; Hypothyroidism, athyreotic; Athyreotic hypothyroidism; Resistance to thyrotropin; Rtsh; Thyrotropin resistance
Definition and Characteristics
Congenital hypothyroidism is frequently (in 80–85% of cases) associated with thyroid dysgenesis. In these cases, the thyroid gland can be absent (agenesis), ectopically located, and/or severely reduced in size (hypoplasia). The most serious effect of untreated congenital hypothyroidism is mental retardation. Absolute arrest of linear growth and bone maturation may also occur. When thyroid hormone therapy is not initiated within the first 2 months of life, neurological complications, such as spasticity and gait abnormalities, dysarthria or mutism, and autistic behavior may develop.
In whites, CHNG2 affects 1 in 5,526 newborns. However, it is strikingly different in blacks: 1 in 32,377 .