TH DNA Sequencing Test (DYT5B)

Test Code

CPT Codes

Preferred Specimen
8 mL whole blood collected in two EDTA (lavender-top) tube
Pediatric (0-3 Years): 2 mL

Minimum Volume
6 mL • Pediatric: 1 mL

Physician Attestation of Informed Consent:This germline genetic test requires physician attestation that patient consent has been received. Non-critical

Please label each specimen tube with two forms of patient identification. These forms of identification must also appear on the test requisition.

Higher blood volumes ensure adequate DNA quantity, which varies with WBC, specimen condition, and need for confirmatory testing. Patients 0-3 years have higher WBC, yielding more DNA per mL of blood.

Notes: DNA yields and quality are better in fresh specimens. However, when necessary, most genetic tests are successful from DNA purified from whole blood that is several days old.

Transport Temperature
Room temperature

Specimen Stability
Room temperature: 10 days
Refrigerated: 10 days
Frozen: Unacceptable

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis

Sanger Sequencing

FDA Status
This test was developed and its analytical performance characteristics have been determined by Athena Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Set up: As needed; Report available: 14-28 days

Reference Range
See Laboratory Report

Clinical Significance
Detects sequence variants in the TH gene in patients with DOPA-responsive Dystonia. Patients exhibit a childhood onset of lower limb dystonia, typically in the foot with possible hyperreflexia and striatal toe. Patients have a dramatic response to low doses of levodopa.

Performing Laboratory
Athena Diagnostics, Inc.
200 Forest Street, 2nd Floor
Marlborough, MA 01752

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.