Arylsulfatase B, Blood Spot

Casandra

Casandra Test Code MC71741Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID ARSBBCPT Codes 82657, 83864

Arylsulfatase B, Blood Spot

Clinical Use

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

Patient's age and reason for testing are required for this test. This test is not useful for carrier detection for MPS VI. In New York, informed consent is required for genetic testing. Several reflex tests and additional analyses, like the quantitation of glycosaminoglycans, might be performed depending on initial results.

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.

Test Details

New York Approved