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Test Code HAD Huntington Disease, Molecular Analysis, Varies

Important Note

This test is only orderable by the laboratory.  To request this test in EPIC, please order LAB001 MAYO MISCELLANEOUS TEST.  Fill out appropriate prompts and request the Mayo test code listed above.

If you need further assistance, please contact the laboratory at 406-414-5010.

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

Method Name

Polymerase Chain Reaction (PCR)

Specimen Type

Varies


Shipping 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:  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 

Reject Due To

All specimens will be evaluated by Mayo Clinic Laboratories for test suitability.

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 testing

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

81271-HTT (huntingtin) (eg, Huntington disease) gene analysis; evaluation to detect abnormal (eg, expanded) alleles

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.