Home
HelpTest Code HAD Huntington Disease, Molecular Analysis, Varies
Useful For
Molecular confirmation of clinically suspected cases of Huntington disease (HD)
Presymptomatic testing for individuals with a family history of HD and a documented expansion in the HTT gene
Special Instructions
Method Name
Polymerase Chain Reaction (PCR)
Reporting Name
Huntington Disease AnalysisSpecimen Type
VariesShipping Instructions
Necessary Information
Molecular Genetics: Neurology Patient Information or a recent clinical note is required. Testing cannot proceed without this information.
Specimen Required
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. For instructions for testing patients who have received a bone marrow transplant, call 800-533-1710.
Specimen Type: Whole blood
Container/Tube: Â Lavender top (EDTA) or yellow top (ACD)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
Additional Information:
1. Specimens are preferred to be received within 4 days of collection. Extraction will be attempted for specimens received after 4 days, and DNA yield will be evaluated to determine if testing may proceed.
2. To ensure minimum volume and concentration of DNA is met, the preferred volume of blood must be submitted. Testing may be canceled if DNA requirements are inadequate.
Specimen Minimum Volume
See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Ambient (preferred) | ||
| Frozen | |||
| Refrigerated | |||
Reference Values
Normal alleles: <27 CAG repeats
Intermediate alleles: 27-35 CAG repeats
Reduced penetrance: 36-39 CAG repeats
Full penetrance: >39 CAG repeats
An interpretive report will be provided.
Day(s) Performed
Wednesday
Report Available
7 to 11 days upon receipt of sufficient clinical information for testingPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
81271-HTT (huntingtin) (eg, Huntington disease) gene analysis; evaluation to detect abnormal (eg, expanded) alleles
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| HAD | Huntington Disease Analysis | 21763-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 52885 | Result Summary | 50397-9 |
| 52886 | Result | 53782-9 |
| 52887 | Interpretation | 69047-9 |
| 52888 | Reason for Referral | 42349-1 |
| 52889 | Specimen | 31208-2 |
| 52890 | Source | 31208-2 |
| 52891 | Released By | 18771-6 |
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.Forms
1. Molecular Genetics: Neurology Patient Information is required.
2. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
3. If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.
For BJH Laboratory Use Only
Laboratory Processing Instructions:
BJH Molecular Diagnostics will forward to the performing laboratory.