Specimen:

Whole Blood

Collection Medium:

Minimum:

Adults - 3 mL whole blood in lavender top tube (EDTA)
Children - 2 mL whole blood in lavender top tube (EDTA)
Testing on smaller volumes than those requested will be attempted.  
However, in some cases, small blood volumes may compromise the ability 
to perform testing.
Testing requires a dedicated collection tube.

Testing
Schedule:

Weekly

Analytic Time:

21 days

Reference Range:

Normal: <27 CAG repeats
Premutation: 27-35 CAG repeats
Reduced Penetrance: 36-39 CAG repeats
Complete Penetrance: >39 CAG repeats

Comments:

Presymptomatic patients must be enrolled in the University of Iowa 
Presymptomatic Huntington Disease Testing protocol or similar protocol 
compliant with the Huntington Disease Society of America's "Guidelines 
for Genetic Testing for HD".  Samples for presymptomatic testing must 
be accompanied by a signed and witnessed consent form from the 
individual being tested.  Contact Division of Medical Genetics 
(319-356-2674) for further information.   Presymptomatic patients under 
the age of 18 will not be tested.  Samples from symptomatic patients 
must be accompanied by a written and signed statement from the ordering 
physician stating he/she believes HD is the cause of the patient's 
symptoms.


Please complete the following two forms and submit to the laboratory 
with the specimen and requisition.

Huntington's Disease Indication Form

Presymptomatic Testing for Huntington Disease / Informed Consent

Methodology:

Polymerase Chain Reaction (PCR) and Southern Blot

Sample
Processing:

Do Not Centrifuge.
Label transport tube with two patient identifiers, date and time of 
collection.
Patient's age and sex is required on requisition for processing.
Relevant clinical information must be submitted with specimen in order 
to provide correct interpretation of test results.
Submit whole blood in original container.

Sample
Storage:

Room temperature for up to 24 hours, then refrigerate the whole blood 
if it is necessary to be held overnight, or weekends, or holidays.

Transport
Instructions:

Recommend express mail or equivalent if not on courier service.
Place requisition into outside pocket of bag.
Ship at ambient temperature.

Instructions:

Specimen must be accompanied by signed consent form for asymptomatic 
patients.  Contact Division of Medical Genetics for counseling 
information.

CPT Code:

83890, 83892, 83894(x2), 83896, 83897, 83898, 83912

See Additional Information:
Huntington Disease Information