Chorea Differential Evaluation

Test Code

36777

CPT Codes
81177, 81271<br /> Limited Access Code

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 each of two EDTA (lavender-top) tubes, or
Pediatric 0-3 years: 2 mL whole blood

Minimum Volume

6 mL • 1 mL pediatric whole blood

Instructions

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

Note: 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.

Transport Temperature

Room temperature

Specimen Stability

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

Methodology
Repeat Expansion Detection by Polymerase Chain Reaction, Southern Blot

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: 14-21 days

Reference Range

(DRPLA)Technical Results:
Normal (<=35)
Borderline (36-47)
Positive (>=48)

Huntington's:
Normal (<=26) Normal
Mutable (27-35) Reduced
Penetrance (36-39) Full
Mutation (>=40)

Clinical Significance

Detects CAG triplet repeat expansion in the ITI5 gene and CAG triplet repeat expansions in the DRPLA gene in patients with chorea, ataxia or progressive myoclonus epilepsy and idiopathic behavior change (may not be present in children).

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.