Test Directory

To confirm the clinical diagnosis of Huntington disease (HD) in affected individuals; to provide pre-symptomatic predictive diagnosis of HD in individuals with positive family history; to identify individuals at risk of having affected offspring.

Specimen Type: Whole Blood

Preferred Collection Container: Lavender Top (EDTA)

Alternate Collection Container: Green Top (Sodium Heparin) or Pale-Yellow Top (ACD Solution B)

Desired Specimen Volume: 5 mL

1. Collect 2 lavender top (EDTA) tubes via venipuncture.
2. Fill tubes to capacity with whole blood.

A DNA Testing for Huntington Disease Waiver signed by the referring health care physician is required for testing.

1. Transport 5 mL of whole blood in the original collection containers.
2. Do not reject specimen if the waiver is not received. Forward samples to Quest and fax the waiver to the referring physician. The waiver must be completed and faxed back to the number on the waiver within 4 days of blood draw.

Referral Testing: Notate on the batch sheet "waiver has been faxed to provider" if not received with the sample.

Transport to the laboratory at room temperature.

• Waivers not received within 8 days from draw will result in test cancellation

See patient report.

This testing methodology may not detect repeat expansions with more than 105 CAG repeats resulting in apparent homozygosity for smaller allele. Large repeat expansion sizes are associated with juvenile onset Huntington's disease.

• Huntington Disease Mutation Analysis
• (CAG)n expansion
• Huntington chorea
• HTT gene CAG repeats