Huntington Disease, Molecular Analysis, Varies
Use
Huntington disease (HD) is an autosomal dominant neurodegenerative disorder characterized by involuntary motor disturbances, cognitive decline, and neuropsychiatric issues. It typically begins in the late 30s or 40s but can present earlier. Molecular testing is crucial for confirming the diagnosis in clinically suspected cases and for presymptomatic testing of individuals with a family history of HD, particularly when a CAG repeat expansion in the HTT gene is documented. The presence of this genetic mutation has significant implications for family members, as it informs them about their risk status and informs reproductive decisions.
Special Instructions
Molecular Genetics: Neurology Patient Information form or recent clinical note is required for testing. New York clients must provide informed consent for genetic testing. Ensure minimum DNA concentration is met; otherwise, testing may be canceled. Appropriate pre- and post-test genetic counseling is recommended for patients undergoing predictive testing. Predictive testing of asymptomatic minors is strongly discouraged.
Limitations
Testing cannot proceed without the required patient information or if the minimum DNA volume and concentration are not met. Results interpretation must consider clinical findings, family history, and other lab data. Predictive testing should first confirm the presence of a CAG-repeat amplification in an affected family member. Errors in results interpretation may occur if provided clinical information is incomplete or inaccurate. Predictive testing for asymptomatic children is not recommended due to ethical considerations.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 21763-8
- 50397-9
- 53782-9
- 69047-9
- 42349-1
- 31208-2
- 18771-6
Result Turnaround Time
7-11 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
Not provided
Container
Lavender top (EDTA) or yellow top (ACD)
Collection Instructions
Invert several times to mix blood. Send whole blood specimen in original tube. Do not aliquot. Specimens are preferred to be received within 4 days of collection.
Patient Preparation
A previous bone marrow transplant from an allogenic donor will interfere with testing.