Table 1 Clinical features and diagnostic tests for RTHβ and RTHα
RTHβ | RTHα |
|---|---|
Typical Clinical Features | |
-Goiter | -Bradycardia |
-Resting tachycardia | -Neurodevelopmental delay |
-Osteoporosis | -Anaemia |
-Short stature | -Skeletal dysplasia |
-Attention deficit disorder | -Dysmorphia |
-Family history (80%) | -Constipation |
Diagnostic Tests | |
-Increased fT3, fT4(Rule out antibody interference) | -Decreased T4/T3 ratio |
-Normal/Elevated TSH | -Normal TSH |
-Normal dialyzed free T4 | -Exon sequencing of TRα |
-Rule out autoimmune thyroiditis (anti-thyroid peroxidase, thyroglobulin, and TSH receptor antibodies) | |
-Check serum markers TH hyperfunction (increased SHBG, ferritin, pro-collagen-1-N-terminal peptide (PINP) and decreased cholesterol in hyperthyroidism but normal in RTH) | |
-Check serum a-GSU and compare with TSH (α-GSU (μg/l)/TSH (mU/l)] × 10 > 1.0 (suggests TSHoma) | |
-Consider pituitary MRI (rule out TSHoma) | |
-Exon sequencing of TRβ | |