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HelpTest Code ARSAW Arylsulfatase A, Leukocytes
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Whole Blood ACDShipping Instructions
For optimal isolation of leukocytes, it is recommended the specimen arrive refrigerated within 6 days of collection to be stabilized. Collect specimen Monday through Thursday only and not the day before a holiday. Specimen should be collected and packaged as close to shipping time as possible.
Specimen Required
Container/Tube:
Preferred: Yellow top (ACD solution B)
Acceptable: Yellow top (ACD solution A)
Specimen Volume: 6 mL
Collection Instructions: Send specimen in original tube. Do not aliquot.
Specimen Minimum Volume
5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood ACD | Refrigerated (preferred) | 6 days | YELLOW TOP/ACD |
| Ambient | 6 days | YELLOW TOP/ACD |
Reference Values
≥62 nmol/h/mg
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.
Day(s) Performed
Preanalytical processing: Monday through Saturday
Assay performed: Tuesday
CPT Code Information
82657
Genetics Test Information
This is the preferred test to rule-out metachromatic leukodystrophy.
Metachromatic leukodystrophy is caused by deficient activity of arylsulfatase A (ARSA) enzyme and is characterized by progressive neurologic changes and leukodystrophy with variable age of onset.
Pseudodeficiency of arylsulfatase A (ARSA) enzyme has been recognized with increasing frequency among patients with other apparently unrelated neurologic conditions as well as among the general population.
Additional studies, such as molecular genetic testing of ARSA (CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies; specify ARSA Gene List ID: IEMCP-WHFH2K), urinary excretion of sulfatides (CTSU / Ceramide Trihexosides and Sulfatides, Random, Urine), and/or histological analysis for metachromatic lipid deposits in nervous system tissue are recommended to confirm a diagnosis.
Report Available
2 to 8 daysSpecimen Retention Time
WBC homogenate: 1 monthReject Due To
| Gross hemolysis | Reject |