Arylsulfatase B, Blood Spot
Use
This test supports the biochemical diagnosis of mucopolysaccharidosis type VI (MPS VI, Maroteaux-Lamy syndrome). MPS VI is an autosomal recessive lysosomal disorder characterized by the deficiency of N-acetylgalactosamine 4-sulfatase (arylsulfatase B), leading to the accumulation of dermatan sulfate. Clinical features and severity are variable, and can include short stature, dysostosis multiplex, degenerative joint disease, coarse facial features, hepatosplenomegaly, corneal clouding, and cardiac disease. Cognitive abilities are generally unaffected. The test provides diagnostic testing for individuals with clinical signs of MPS VI. Additional biochemical or molecular testing is required to confirm a diagnosis if an enzyme deficiency is detected.
Special Instructions
Not provided.
Limitations
Enzyme levels may appear normal in individuals undergoing enzyme replacement therapy or post stem cell transplant, which could affect detection reliability. Individuals with pseudodeficiency alleles may show reduced enzyme activity, causing potential diagnostic confusion. Carrier status (heterozygosity) cannot be reliably detected by this test.
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
Arylsulfatase B
Analyte
LOINC Codes
- 55912-0 - Arylsulfatase DBS-cCnc
- 55912-0 - Arylsulfatase DBS-cCnc
- 42349-1
- 59462-2 - Clinical biochemist review
- 18771-6 - Provider signing name
Result Turnaround Time
3-9 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
2 mL
Minimum Volume
0.5 mL
Container
Lavender top (EDTA); acceptable Yellow top (ACD)
Collection Instructions
Send whole blood specimen in original tube. Do not aliquot.
Causes for Rejection
Blood spot specimen that shows serum rings or has multiple layers; Insufficient specimen; Unapproved filter papers
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 7 days |
| Frozen | 60 days |
