Test Code SBULB Spinobulbar Muscular Atrophy (Kennedy Disease), Molecular Analysis, Varies
Useful For
Molecular confirmation of clinically suspected cases of sporadic or familial spinobulbar muscular atrophy (SBMA)
Presymptomatic testing for individuals with a family history of SBMA and a documented expansion in the androgen receptor (AR) gene
Special Instructions
Reporting Name
Spinobulbar Musc Atrophy, Kennedy'sSpecimen Type
VariesShipping Instructions
Specimen Required
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. For information about testing patients who have received a bone marrow transplant, call 800-533-1710.
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA) or yellow top (ACD)
Acceptable: None
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
Specimen Stability Information: Ambient (preferred) 4 days/Refrigerated 4 days/Frozen 4 days
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 requested volume must be submitted. Testing may be canceled if DNA requirements are inadequate.
Specimen Type: Extracted DNA
Container/Tube:
Preferred: Screw Cap Micro Tube, 2mL with skirted conical base
Acceptable: Matrix tube, 1mL
Collection Instructions:
1. The preferred volume is at least 100 mcL at a concentration of 75 ng/mcL.
2. Include concentration and volume on tube.
Specimen Stability Information: Frozen (preferred) 1 year/Ambient/Refrigerated
Additional Information: DNA must be extracted in a CLIA-certified laboratory or equivalent and must be extracted from a specimen type listed as acceptable for this test (including applicable anticoagulants). Our laboratory has experience with Chemagic, Puregene, Autopure, MagnaPure, and EZ1 extraction platforms and cannot guarantee that all extraction methods are compatible with this test. If testing fails, one repeat will be attempted, and if unsuccessful, the test will be reported as failed and a charge will be applied. If applicable, specific gene regions that were unable to be interrogated due to DNA quality will be noted in the report.
Specimen Minimum Volume
See Specimen Required
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Varies | Varies |
Reject Due To
All specimens will be evaluated by Mayo Clinic Laboratories for test suitability.Reference Values
Normal alleles: 11-34 CAG repeats
Abnormal alleles: 36-62 CAG repeats
The interpretive report includes an overview of the findings as well as the associated clinical significance.
Day(s) Performed
Varies
Report Available
14 to 21 daysPerforming Laboratory

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.CPT Code Information
81204-AR (androgen receptor)(eg, spinal and bulba muscular atrophy, Kennedy disease, X chromosome inactivation) gene analysis; characterization of alleles (eg, expanded size or methylation status)
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
SBULB | Spinobulbar Musc Atrophy, Kennedy's | 35359-9 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
53341 | Result Summary | 50397-9 |
53342 | Result | 82939-0 |
53343 | Interpretation | 69047-9 |
53344 | Reason for Referral | 42349-1 |
53345 | Specimen | 31208-2 |
53346 | Source | 31208-2 |
53348 | Released By | 18771-6 |
Forms
1. 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)
2. Molecular Genetics: Neurology Patient Information
3. If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.
Testing Algorithm
For information see Inherited Motor Neuron Disease and Dementia Testing Algorithm