Hypothyroidism in children with the Down syndrome: report of three cases.

The cases of three patients with concurrent Down syndrome and hypothyroidism are reported. Review of these and 12 similar cases from the literature suggests an association between the Down syndrome and thyroid autoimmune disease. Studies of autoimmune thyroid antibodies in families of patients with the Down syndrome are also reviewed. Several questions as yet unanswered regarding the possible relationship of these studies to cases of concurrent Down syndrome and hypothyroidism are mentioned.