Thyroid Hormone Receptor Beta: THRB Sequencing

Diagnostic Use

Resistance to thyroid hormone (RTH), with elevated serum free thyroid hormones and non-suppressed thryrotropin levels, is either relatively asymptomatic, suggesting a generalized disorder (GRTH) or associated with thyrotoxic features, indicating possible selective pituitary resistance (PRTH). Analysis of exons 7 to 10 of the THRB gene may detect between 95% and 100% of all mutations in patients with Generalised Resistance to Thyroid Hormone (GRTH).

Department

Genetics - Molecular Pathology

Delphic Registration Code

MOLP

Constituent Tests

• Genomic DNA Extraction

Synonyms

GRTH
Resistance to thyroid hormone

Turnaround Time

4 weeks

Test Code

7302

Specimen Type

• Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

4.0

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

1.0

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

This test requires nucleated cells. Please do not centrifuge or freeze blood samples.
If storing blood tube prior to delivery please refrigerate at 4 degrees (transport still at ambient temperature).

Aliquot Instructions

Sample Type

• Whole Blood

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Additional Referral/Aliquot Information

Please do not centrifuge or freeze blood samples.
If storing blood tube prior to delivery please refrigerate at 4 degrees (transport still at ambient temperature).

Test Method

Exons 7 to 10 of the Thyroid Hormone Receptor Beta (THRB) gene are amplified using PCR and analysed by DNA sequencing.

Contact Canterbury Health Laboratories on +64 3 364 0484 or email LabInfo@cdhb.health.nz

Uncertainty of Measurement:
Automated bidirectional DNA sequencing has an analytical sensitivity and specificity of >99%. Note that the lower limit of variant detection of sequencing analysis is ~10%, this is important to consider in the case of mosaicism, mitochondrial, and somatic variation that is not expected to be present at 50% or 100%. This analysis will not detect variants located within intronic regions, except at the intron-exon boundaries.

Genomic DNA must be extracted from the specimen prior to testing. This incurs an additional charge (see GDNA). Laboratories may prefer to submit DNA for testing. Please provide a minimum of 5 micrograms of DNA at 20 nanograms/microlitre.

Contact Information

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