Sign in →

Test Code ARSAW Arylsulfatase A, Leukocytes

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Reporting Name

Arylsulfatase A, Leukocytes

Specimen Type

Whole Blood ACD


Shipping 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.


Reject Due To

Gross hemolysis Reject

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

Specimen Minimum Volume

5 mL

Day(s) Performed

Preanalytical processing: Monday through Saturday

Assay performed: Tuesday

Specimen Retention Time

WBC homogenate: 1 month

Report Available

2 to 8 days

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.

Useful For

Preferred enzymatic test for detection of arylsulfatase A deficiency

 

This test is not suitable for carrier detection.

CPT Code Information

82657

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ARSAW Arylsulfatase A, Leukocytes 24078-8

 

Result ID Test Result Name Result LOINC Value
8779 Arylsulfatase A, Leukocytes 24078-8
32437 Interpretation 59462-2
32438 Reason for referral 42349-1
32439 Reviewed by 18771-6

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.

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.