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Diagnostic Services

Genetics Lab


Fucosidosis Enzyme Assay

Fucosidosis presents with progressive mental retardation and neurologic deterioration caused by a deficiency of lysosomal alpha-fucosidase, an enzyme involved in the cleavage of fucose from large branched sugar molecules. The clinical spectrum is varied from mild to severe including coarsening of facial features, hepatosplenomegaly, and dysostosis multiplex. Cherry red spots of the macula may be present on ophthalmology evaluation. Sweat chloride may be elevated. The milder form may include angiokeratomas and the presence of twisted blood vessels within the membrane covering of the eyeball and inner eyelid.

Test Name: Fucosidosis (alpha-fucosidase)
Test Code:
Test Description:
This test is a quantitative assay of alpha-fucosidase in white blood cells or cultured fibroblasts.
alpha fucosidase; alpha fucosidosis
This test is used to diagnose fucosidosis in a child with:
-progressive mental retardation
-neurologic deterioration
-abnormal urine oligosaccharide pattern
This test is not appropriate for determining carrier status or for prenatal diagnosis.
Related Tests: Oligosaccharides, Urine  
This test is used to screen patients with neurodegenerative symptoms suggestive of a glycoprotein storage disorder.

Clinical Links: Fucosidosis OMIM entry
Performed weekly
Turnaround Time:
7-10 days
Fluorometic enzymatic assay
Reference Range:
Interpretive report is provided
Consent Form:
Sample Requirements: Type
Whole blood: 5-10 ml, ACD (yellow) or Heparin (green) tube. Do NOT use gel separator tubes.
Fibroblasts: 2 T-25 flasks
Skin biopsy: 2-4 mm skin punch biopsy

Do not spin. Keep at room temperature.

Transport Mon - Thurs at room temperature via overnight shipping. Blood sample MUST be processed within 24 hours.
Samples Received:
Monday -Friday 8 am - 5 pm PST. For Thursday shipping please ensure Friday AM delivery.
Special Considerations:
If fresh skin biopsy is submitted, fibroblast culture (CH-SKIN) must be ordered separately. Call to discuss.
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