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HelpTest Code Billings Clinic: 8956 Mayo: ARSU Arylsulfatase A, 24 Hour, Urine
Reporting Name
Arylsulfatase A, UPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
Detection of arylsulfatase A deficiency using urine specimens
This test is not suitable for carrier detection.
Method Name
Colorimetric, Enzyme Assay
Ordering Guidance
The preferred test to rule-out metachromatic leukodystrophy is ARSAW / Arylsulfatase A, Leukocytes.
Shipping Instructions
Specimen must be received at least 1 day prior to assay day for processing.
Necessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Supplies: Urine Tubes, 10 mL (T068)
Container/Tube: Plastic, 10-mL tube
Specimen Volume: 6 mL
Collection Instructions:
1. Collect a 24-hour urine specimen.
2. No preservative.
3. Refrigerate specimen during collection.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Specimen Type
UrineSpecimen Minimum Volume
2.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated | 14 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
≥19 nmol/h/mL
Note: Results from this assay may not reflect carrier status because of individual variation of arylsulfatase A enzyme levels. Low normal values may be due to the presence of pseudodeficiency or carrier alleles. Patients with these depressed levels may be phenotypically normal.
Interpretation
Reduced levels of arylsulfatase A are seen in patients with metachromatic leukodystrophy (MLD).
Individuals with pseudodeficiency of arylsulfatase A can have results in the affected range but are otherwise unaffected with MLD.
Abnormal results should be confirmed using CTSA / Ceramide Trihexosides and Sulfatides, Urine. If molecular confirmation is desired, consider molecular genetic testing of ARSA (CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies; specify Gene List ID: IEMCP-WHFH2K).
Day(s) Performed
Tuesday
Report Available
9 to 16 daysTest 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
84311
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| ARSU | Arylsulfatase A, U | 42726-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8777 | Arylsulfatase A, U | 42726-0 |
| 37423 | Interpretation (ARSU) | 59462-2 |
| 37413 | Reviewed 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. Biochemical Genetics Patient Information (T602)
3. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Special Instructions
Testing Algorithm
See Lysosomal Storage Disorders Diagnostic Algorithm, Part 2