Establishing Appropriate Thyroid Hormone Reference Values in Down Syndrome Patients

This cross-sectional study of 503 individuals with Down syndrome identified specific thyroid hormone reference ranges (TSH: 0.88-11.25 mIU/L; FT4: 0.71-1.63 ng/dL) that differ from general population norms, to prevent overdiagnosis and inappropriate treatment of subclinical hypothyroidism. The findings suggest current diagnostic approaches may lead to unnecessary hormone replacement therapy in people with Down syndrome due to reliance on standard reference intervals.