Complete Dopa-Responsive Dystonia (DYT5) Evaluation

Test Code

93970

CPT Codes
81405, 81406, 81479 CPT coding may differ dependent on payer rules which may impact prior authorization testing. Please direct any questions regarding CPT coding to the payer being billed.

Physician Attestation of Informed Consent

This germline genetic test requires physician attestation that patient consent has been received if ordering medical facility is located in AK, DE, FL, GA, IA, MA, MN, NV, NJ, NY, OR, SD or VT or test is performed in MA.

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

Instructions

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 Container

EDTA (lavender-top) tube

Transport Temperature

Room temperature

Specimen Stability

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

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

Gross hemolysis • Received frozen

Methodology
Sanger Sequencing • Multiplex Ligation-dependent Probe Amplification (MLPA)

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

As needed

Reference Range

See Laboratory Report

Clinical Significance

Detects mutations in the GCH1 and TH genes. Indications include: Childhood onset of dystonia with positive response to low dose levodopa. Childhood onset of lower limb dystonia, typically in the foot with possible hyperreflexia and striatal toe. Dramatic response to low doses of levodopa.

Performing Laboratory

Athena Diagnostics, Inc.

200 Forest Street, 2nd Floor

Marlborough, MA 01752-3023

Last Updated: November 6, 2024

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.