Ordering Recommendation

Use to confirm a diagnosis of Huntington disease (HD) in symptomatic individuals. May be used for presymptomatic testing in adults with a family history of HD.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B).

Specimen Preparation

Transport 2 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated. Also acceptable: Ambient.

Unacceptable Conditions

A completed HD-specific consent form, signed by the patient (or legal guardian) and physician, is required for all specimens. Testing for asymptomatic patients under the age of 18 years is not offered. Presymptomatic patients are strongly encouraged to be tested through a counseling program approved by the Huntington Disease Society of America at 800-345-4372. Call Genetics Processing with additional questions at 800-242-2787 ext. 3301.


Room temperature: 1 week; Refrigerated: 1 month; Frozen: Unacceptable


Polymerase Chain Reaction (PCR)/Fragment Analysis




7-10 days

Reference Interval

Interpretive Data

Refer to report.

Compliance Category

Laboratory Developed Test (LDT)


Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
3016909 Huntington Disease Specimen 31208-2
3016910 Huntington Disease Allele 1 49637-2
3016911 Huntington Disease Allele 2 49638-0
3016912 Huntington Disease Interpretation 50621-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • HD genetic testing
  • HTT genetic testing
Huntington Disease (HD) CAG Repeat Expansion