Euthyroid Submedian Free T4 and Subclinical Hypothyroidism May Have a Detrimental Clinical Effect in Down Syndrome

Abstract

SCH and euthyroid submedian FT4 may have significant clinical sequelae, such as hypotonia and anemia. Interventional studies with L-thyroxine replacement may be indicated in these subpopulations. Our finding that FT4 levels decrease with age in DS (contrasting the general population trend) may indicate redefining the normal FT4 levels range in DS.