- Resistance to thyroid hormone defined biochemically as elevated levels of T3 and/or T4 with non-suppressed TSH levels
- A high likelihood that the phenotype is completely explained by an acquired aetiology (eg drugs, assay interference, iodine deficiency, TSH-secreting pituitary tumour).
- A pathogenic mutation in a known causative gene which completely explains the phenotype.
Prior genetic testing guidance:
- Results should have been reviewed for all genetic tests undertaken, including disease-relevant genes in exome sequencing data. The patient is not eligible if they have a molecular diagnosis for their condition.
- Genetic testing should continue according to routine local practice for this phenotype regardless of recruitment to the project; results of these tests must be submitted via the ‘Genetic investigations’ section of the data capture tool to allow comparison of WGS with current standard testing.
PLEASE NOTE: The sensitivity of WGS compared to current diagnostic genetic testing has not yet been established. It is therefore important that tests which are clinically indicated under local standard practice continue to be carried out.
Prior genetic testing genes:
Testing of the following genes should be carried out PRIOR TO RECRUITMENT where this is in line with current local practice:
- Elevated T3, low/normal T4 and/or clinical features suggestive of Allan-Herndon-Dudley syndrome: SLC16A2 (MCT8)
- Elevated T3, low/normal T4, and/or clinical features suggestive of RTHalpha: THRA Raised T4, normal/low T3, high reverse T3, low plasma selenium: SECISBP2, TRNAU1
These requirements will be kept under continual review during the main programme and may be subject to change.