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If you have additional questions regarding this test, please call: 415-353-1667
Huntington's Disease Triplet Repeat
|Utilization Guidelines||Tests with long turn-around times (ie. Molecular based tests and Microarrays) should only be requested on an inpatient if the result is going to affect the inpatient management.
If the patient will likely be discharged before the result will be available, the test should be requested after discharge. (NOTE: UCSF Medical Center is not reimbursed for inpatient testing).
An exception to the above may be appropriate if there is a possibility the patient will not survive to be discharged and the information is important for diagnosis and/or family decisions/management (ie. recurrence risk).
|Performed by||Medical Genomics - Molecular Diagnostics|
|In House Availability||Run 1x per week as needed, Tuesday or Thursday, day shift only|
|Method||PCR and Southern blot|
|Collection Instructions||All patients must receive genetic counseling prior to pre-symptomatic Huntingtons testing. The name of the genetic counselor who provided counseling must be included on the test requisition. For counseling contact Andrea Zanko in Genetics at 476-9320
If collecting in citrate, check the expiration date on the label of the blue top vacutainer before drawing the patient.
Do not collect sample in heparin. Keep sample refrigerated for overnight or longer storage.
For UCSF Samples (from remote sites) Click here for sample collection instructions
For NON-UCSF Samples Click here for Requisition form & Account set-up instructions. Note we only do institutional billing.
|Container type||Lavender top preferred, Blue top and Yellow (ACD) tops acceptable|
|Amount to Collect||3 mL blood|
|Sample type||EDTA, citrated or ACD whole blood|
|Preferred volume||3 mL blood|
|UCSF Rejection Criteria||Inadequate sample. Samples collected in heparin.|
|Processing notes||Do not centrifuge the specimen. Store at room temperature. Refrigerated samples are acceptable.|
|Normal range||Normal, CAG repeat sizes less than 27.|
|Synonyms||Huntington chorea; HTT|
|Turn around times||7-10 days|
|Additional information|| An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
The results for this test will not be available in APEX to safeguard patient confidentiality. All Huntington's results are referred to Genetic Counselor Jamie C. Fong and must be obtained from her at (415) 476-8613.
Results are reported as "Normal", "Normal but potentially unstable", "Abnormal with variable penetrance; unstable" or "Abnormal with full penetrance".
The number of CAG repeats adjacent to the HTT gene is also reported.
This test was developed and its performance characteristics determined by the Clinical Laboratories at the Medical Center at UC San Francisco. It has not been cleared or approved by the U.S. Food and Drug Administration.
|LDT or Mod FDA?||Yes|
|Last Updated||8/17/2016 11:11:02 PM|