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Test ID: FUCW Alpha-Fucosidase, Leukocytes

Reporting Name

Alpha-Fucosidase, Leukocytes

Useful For

Detection of fucosidosis

 

This test is not useful for establishing carrier status for fucosidosis.

Clinical Information

Fucosidosis is an autosomal recessive lysosomal storage disorder caused by reduced or absent alpha-L-fucosidase enzyme activity. This enzyme is involved in degrading asparagine-linked, fucose-containing complex molecules (oligosaccharides and glycoasparagines) present in cells. Reduced or absent activity of this enzyme results in the abnormal accumulation of these molecules in the tissues and body fluids.

 

Severe and mild subgroups of fucosidosis, designated types I and II, have been described, although recent data suggests individual patients may represent a continuum within a wide spectrum of severity. The more severe type is characterized by infantile onset, rapid psychomotor regression, and severe neurologic deterioration. Additionally, dysostosis multiplex and elevated sweat sodium chloride are frequent findings. Death typically occurs within the first decade of life. Those with the milder phenotype express comparatively mild psychomotor and neurologic regression, radiologic signs of dysostosis multiplex and skin lesions (angiokeratoma corporis diffusum). Normal sweat salinity, the presence of the skin lesions, and survival into adulthood most readily distinguish milder from more severe phenotypes. Although the disorder is panethnic, the majority of reported patients with fucosidosis have been from Italy and southwestern United States. To date, about 100 cases have been reported worldwide.

 

An initial diagnostic workup includes a urine screening assay for several oligosaccharidosis (OLIGU / Oligosaccharide Screen, Random, Urine). If the screening assay is suggestive of fucosidosis, enzyme analysis of alpha-L-fucosidase can confirm the diagnosis.

Interpretation

Values below 0.32 nmol/min/mg protein are consistent with a diagnosis of fucosidosis.

Testing Algorithm

See Lysosomal Storage Disorders Diagnostic Algorithm, Part 1 in Special Instructions.

Analytic Time

30 days

Day(s) and Time(s) Performed

Varies

Clinical Reference

1. Cowan TM, Yu C: Laboratory investigations of inborn errors of metabolism. In Pediatric Endocrinology and Inborn Errors of Metabolism. Edited by K Sarafoglou, GF Hoffmann, KS Roth, New York, McGraw-Hill Medical Division, 2009, pp 867-868

2. Enns GM, Steiner RD, Cowan TM: Lysosomal disorders. In Pediatric Endocrinology and Inborn Errors of Metabolism. Edited by K Sarafoglou, GF Hoffmann, KS Roth, New York, McGraw-Hill Medical Division, 2009, pp 747-748

3. Thomas GH: Disorders of Glycoprotein Degradation: alpha-Mannosidosis, beta-Mannosidosis, Fucosidosis, and Sialidosis. In The Online Metabolic and Molecular Bases of Inherited Disease. Edited by D Valle, AL Beaudet, B Vogelstein, et al. New York, McGraw-Hill. Accessed March 18, 2019, Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225545029&bookid=2709&Resultclick=2

Method Name

Fluorometric

Specimen Type

Whole Blood ACD


Advisory Information


If clinically suspicious of an oligosaccharidosis, a screening test is available. Order OLIGU / Oligosaccharide Screen, Random, Urine.



Shipping Instructions


For optimal isolation of leukocytes, it is recommended the specimen arrive refrigerate within 144 hours of collection to be stabilized. Collect specimen Monday through Thursday only and not the day before a holiday. Specimen should be Collected and packaged as close to shipping time as possible.



Specimen Required


Container/Tube:

Preferred: Yellow top (ACD solution B)

Acceptable: Yellow top (ACD solution A)

Specimen Volume: 6 mL

Collection Instructions: Send specimen in original tube. Do not transfer blood to other containers.


Specimen Minimum Volume

5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood ACD Refrigerated (preferred) 6 days YELLOW TOP/ACD
  Ambient  4 days YELLOW TOP/ACD

Reference Values

≥0.32 nmol/min/mg protein

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

82657

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FUCW Alpha-Fucosidase, Leukocytes 24047-3

 

Result ID Test Result Name Result LOINC Value
8814 Alpha-Fucosidase, Leukocytes 24047-3
35635 Interpretation (FUCW) 59462-2
35634 Reviewed By 18771-6

Forms

1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

2. Biochemical Genetics Patient Information (T602) in Special Instructions

3. If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.

Mayo Clinic Laboratories | Neurology Catalog Additional Information:

mml-Pediatric, mml-Neurometabolic