Thyroid dysfunction in children with Down syndrome: A literature review

Introduction: This article is an evidence-based review of thyroid disease in children with Down syndrome, including a comparison between various professional guidelines for the management of thyroid disease in children with Down syndrome. Aspects of thyroid disease which are discussed include: congenital hypothyroidism; autoimmune thyroid disease; subclinical hypothyroidism; and hyperthyroidism. The national professional guidelines of Ireland, the United Kingdom, the United States of America, Australia and Canada are reviewed and compared. Materials and methods: A literature search was conducted using Medline and PubMed. Search terms included 'Down syndrome' and 'thyroid disease', 'hypothyroidism', 'hyperthyroidism', 'subclinical hypothyroidism'. Results: Eighty-nine articles were retrieved and reviewed for inclusion. The guidelines on the medical management of children with Down syndrome of five expert groups have also been retrieved and reviewed for this discussion. These various guidelines offer largely similar advice regarding frequency of thyroid function tests, with only Ireland and the UK testing less frequently than annually. Only the United Kingdom and Irish Down Syndrome Medical Interest Group guidelines suggest testing for thyroid antibodies at every thyroid screen. None of the guidelines offer suggestions on the optimal course of action to pursue after the discovery of subclinical hypothyroidism. Conclusion: In conclusion, more evidence is required regarding the optimal course of treatment for subclinical hypothyroidism. Such evidence may be best obtained by conducting a prospective randomized control trial.