Autoimmune thyroiditis in infants with Down's syndrome.

Children with Down's syndrome are at high risk of thyroid dysfunction, including autoimmune thyroiditis. We describe two infants with Down's syndrome in whom chronic autoimmune thyroiditis was diagnosed at ages 5 months and 8 months. We suggest that follow-up of thyroid function and thyroid autoantibodies should be started from infancy in Down's syndrome to prevent further deterioration of mental development and growth.