What condition relates to an underactive thyroid that can lead to intellectual disabilities?

Congenital hypothyroidism is indeed the condition associated with an underactive thyroid that can lead to intellectual disabilities. This condition occurs when the thyroid gland does not produce enough thyroid hormone, which is crucial for the development of the brain and body, particularly during the early stages of life. If left untreated, congenital hypothyroidism in infants and young children can result in severe cognitive impairments, growth issues, and other developmental delays.

Early diagnosis and treatment, often via hormone replacement therapy, can significantly mitigate these risks and enable children with congenital hypothyroidism to develop normally. This highlights the importance of newborn screening for thyroid function, as timely intervention is key to preventing intellectual disabilities associated with this condition. In contrast, the other options relate to genetic syndromes and environmental factors that have different etiology and implications for cognitive development.