Ordering Recommendation
Diagnostic confirmation for Huntington disease (HD) in a symptomatic individual. Presymptomatic testing for adults with a family history of HD.
Mnemonic
Methodology
Polymerase Chain Reaction (PCR)/Fragment Analysis
Performed
Varies
Reported
7-10 days
New York DOH Approval Status
Specimen Required
Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B).
Transport 3 mL whole blood. (Min: 1 mL)
Refrigerated. Also acceptable: Ambient.
A completed HD-specific consent form, signed by the patient (or legal guardian) and physician, is required for all specimens. Testing for patients under the age of 18 years or fetal specimens 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
Reference Interval
Interpretive Data
Refer to report
Allele type |
Number of CAG Repeats |
---|---|
Normal allele | Less than or equal to 26 |
Mutable normal (intermediate) allele | 27-35 |
HD allele with reduced penetrance | 36-39 |
HD allele with full penetrance | Greater than or equal to 40 |
Laboratory Developed Test (LDT)
Note
Hotline History
Hotline History
CPT Codes
81271
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0050604 | Huntington Disease (HD) Allele 1 | 49637-2 |
0050606 | Huntington Disease (HD) Allele 2 | 49638-0 |
0050607 | Huntington Disease (HD) Interpretation | 50621-2 |
2001353 | Huntington Disease (HD) - Specimen | 31208-2 |
Aliases
- HD genetic testing
- HTT genetic testing