Skip to main content

Diagnostic Services

Genetics Lab


Mucopolysaccharidosis Type VI (Maroteaux-Lamy) Enzyme Assay

Maroteaux-Lamy (MPS VI) is a lysosomal storage disorder caused by a deficiency of the enzyme arylsulfatase B. This deficiency leads to an accumulation of cellular carbohydrates called glycosaminoglycans (GAG) within the lysosomes of cells in the bones, joints, heart, liver and spleen and other tissues. Individuals with MPS VI typically have normal intelligence but can have significant bone deformities (dysostosis multiplex), limited range of motion, enlarged liver and spleen, cardiac and valvular disease and many other organ complications. There is a wide spectrum of disease severity and progression. There is now an FDA-approved enzyme replacement therapy for the primary treatment of MPS VI.

Test Name: Maroteaux-Lamy (Arylsulfatase B)
Test Code:
Test Description:
Measurement of arylsulfatase B in white blood cells or cultured fibroblasts.
arylsulfatase B; MPS VI; mucopolysaccharidosis
This test is indicated for individuals with elevated quantitative excretion of glycosaminoglycan, and who have also had MPS electrophoresis indicating elevated excretion of dermatan sulfate. This test is not appropriate for determining carrier status or for prenatal diagnosis.
Related Tests: Mucopolysaccharide Quantitative Urine  
Quantitative measurement of total glycosaminoglycan excretion in the urine relative to the level of creatinine in the urine. This test is used to screen individuals suspected of having a mucopolysaccharidosis.

Mucopolysaccharide electrophoresis  
This is a follow-up test to mucopolysaccharide quant or metabolic screen to determine the pattern of elevated GAG excretion.

Clinical Links:
Performed weekly, not available STAT
Turnaround Time:
7-10 days
Fluorometric enzyme assay
Reference Range:
Interpretive report provided
Consent Form:
Sample Requirements: Type
Whole Blood: 10ml ACD (yellow) or heparin (green) tube
Fibroblasts: 2 T-25 flasks
Skin Biopsy: 2-4mm skin punch biopsy

Do not spin. Keep at room temperature

Ship overnight at room temperature. Blood sample MUST be received within 24 hours of collection. Transport fibroblasts/biopsy in appropriate media.
Samples Received:
Mon - Fri 8:00am - 5:00pm PST. For Thursday shipment please select Friday AM courier delivery.
Special Considerations:
For fresh skin biopsy samples, Fibroblast Culture (CH-SKIN) must be ordered separately.
Please e-mail Client Services or call at 206-987-2617 with any billing questions
CPT Code:
Please e-mail Client Services or call at 206-987-2617 with any billing questions