Mucopolysaccharidosis IV Enzyme Panel, Leukocytes

Casandra

Casandra Test Code MC51371Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID MPS4WCPT Code 82657

Mucopolysaccharidosis IV Enzyme Panel, Leukocytes

Clinical Use

Use

This test supports the biochemical diagnosis of mucopolysaccharidosis type IVA and IVB in whole blood specimens. Mucopolysaccharidosis type IVA (Morquio A syndrome) is caused by reduced or absent N-acetylgalactosamine-6-sulfate sulfatase (GALNS) enzyme activity, leading to accumulation of glycosaminoglycans in tissues. Mucopolysaccharidosis type IVB (Morquio syndrome B) involves reduced beta-galactosidase activity, causing systemic skeletal disorders. The test aids in assessing diseases characterized by these enzyme deficiencies. Additional biochemical or molecular testing is required to confirm a diagnosis if enzyme deficiency is detected.

Special Instructions

Patient's age and reason for testing are required. Specimen should arrive refrigerated within 6 days of collection for optimal leukocyte isolation. Collect specimen Monday through Thursday only, avoiding the day before a holiday. Original blood tube should be sent without aliquoting.

Limitations

This test is not useful for carrier detection. Individuals with pseudodeficiency alleles or those receiving enzyme replacement therapy may show reduced enzyme activity. Beta-galactosidase is also reduced in patients with galactosialidosis, and such patients need follow-up testing for neuraminidase, which this panel does not evaluate. Carrier status cannot be reliably detected, and enzyme levels may be normal in patients undergoing hematopoietic stem cell transplant.

Test Details

New York Approved