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 | |