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Diagnostic Services

Genetics Lab


Mucopolysaccharidosis Type I (Hurler, Hurler/Scheie, Scheie) Enzyme Assay

Mucopolysaccharidosis type I is a multisystem, progressive disorder caused by a deficiency of alpha-iduronidase. This enzyme is involved in the breakdown and recycling of glycosaminoglycans (GAG), which are complex carbohydrate components of cells. Deficiency of the alpha-iduronidase enzyme leads to accumulation of heparan and dermatan sulfate in multiple body tissues and can cause coarse facial features, corneal clouding, cardiac involvement, skeletal dysplasia, joint stiffness and developmental delay. Age of onset and clinical severity is variable.

Test Name: Hurler (alpha-iduronidase)
Test Code:
Test Description:
Measurement of alpha-iduronidase in white blood cells or cultured fibroblasts.
MPS I; Hurler syndrome; alpha-iduronidase
This test is indicated for individuals with elevated quantitative excretion of glycosaminoglycan, and who have also had MPS electrophoresis indicating elevated excretion of heparan and 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: Mucopolysaccharidosis Type I GeneReview
Performed weekly
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

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. 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