Test Overview
Test Methodology

Polymerase Chain Reaction

Test Usage

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

Reference Range *

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.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Wednesday
Analytic Time

8 - 12 days

Soft Order Code
HAD
Laboratory
Sendout
Reference Laboratory
Mayo HAD
Section
Special Testing
Specimen Requirements
Collection Instructions

Collect specimen in lavender or yellow top tube. Invert several times to mix. Send to Specimen Processing at ambient temperature. Specimen preferred to arrive at Mayo within 96 hours of collection.

Special Handling

Specimen preferred to arrive at Mayo within 96 hours of collection.

Alternate Specimen
Any anticoagulant is acceptable
Normal Volume
3 mL whole blood
Minimum Volume
1 mL whole blood
Storage Temperature
Ambient preferred, frozen or refrigerated acceptable. Specimen preferred to arrive at Mayo within 96 hours of collection
Additional Information

Test performed by Mayo Clinic Laboratories

Billing
CPT Code
81271