Down syndrome is associated with increased prevalence of which thyroid condition?

• A. Graves' disease
• B. Hashimoto's thyroiditis
• C. Thyroid cancer
• D. Thyroid dysgenesis

Answer: (D)

Down syndrome carries a higher risk of thyroid dysfunction, including congenital problems with the thyroid gland. Thyroid dysgenesis refers to developmental abnormalities of the thyroid (such as agenesis, hypoplasia, or ectopy) that lead to hypothyroidism from birth. This congenital, structural issue is more commonly observed in infants with Down syndrome than in the general population, making thyroid dysgenesis a fitting association. Autosimmune thyroid diseases like Hashimoto’s or Graves’ can occur as well, but the question’s focus on a congenital thyroid abnormality aligns best with dysgenesis.