NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Detection of fucosidosis
Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request
Unless fucosidosis is the only lysosomal storage disease being considered, fibroblasts are preferred since they provide a long-term source of all of the lysosomal enzymes.
Not recommended for carrier detection.
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Specimen Type Describes the specimen type needed for testing
Whole Blood ACD
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Specimen must arrive within 144 hours of draw to be stabilized. Draw specimen Monday through Thursday only and not the day before a holiday. Specimen should be drawn and packaged as close to shipping time as possible.
Preferred: Yellow top (ACD solution B)
Acceptable: Yellow top (ACD solution A)
Specimen Volume: 6 mL
Collection Instructions: Do not transfer blood to other containers.
1. 1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (Supply T576) is available in Special Instructions.
2. 2. If not ordering electronically, submit a Biochemical Genetics Request Form (Supply T439) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild OK; Gross reject
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Whole Blood ACD||Refrigerated (preferred)||6 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
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, glycoasparagines) present in cells. Reduced or absent activity of this enzyme results in the abnormal accumulation of these undigested molecules in the tissues and body fluids. Although the disorder is panethnic, the majority of reported patients with fucosidosis have been from Italy and southwestern United States. To date, less than 80 patients have been reported in the literature.
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.
A diagnostic workup includes urine thin-layer chromatography (OLIGO / Oligosaccharide Screen, Urine), which may reveal the characteristic banding pattern associated with fucosidosis. In addition, enzyme assay of alpha-L-fucosidosis can confirm the diagnosis. Unless fucosidosis is the only lysosomal storage disease being considered, fibroblasts are preferred since they provide a long-term source of all of the lysosomal enzymes. Enzyme analysis should be pursued in cases with strong clinical suspicion regardless of the urine screening result. Sequencing of the FUCA1 gene allows for detection of disease-causing mutations in affected patients and identification of familial mutations allows for testing of at-risk family members.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
> or =0.32 nmol/min/mg protein
Low alpha-fucosidase suggests fucosidosis when accompanied with the clinical findings discussed above. Occasionally, values below the normal range occur. Since significant activity is present in those patients, these results do not suggest fucosidosis.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Low alpha-fucosidase variants in serum have been shown in the absence of fucosidosis. Though this has been associated with ovarian cancer, it is not a consistent finding and makes serum testing for fucosidosis unreliable.
If lysosomal storage diseases other than fucosidosis are being considered, the most appropriate test to order is FUCT / Alpha-Fucosidase, Fibroblasts; fibroblasts are preferred since the cultured cells can be used for additional lysosomal enzyme testing in the future as needed.
The current laboratory procedure is for disease testing only. Carrier status detection by this method is not possible as normal individuals may exhibit rather low levels of alpha-fucosidase activity.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
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 Scriver's The Online Metabolic and Molecular Basis of Inherited Disease (OMMBID) Edited by D Valle et al, McGraw-Hill Companies, Inc. Available from URL: http://www.ommbid.com/OMMBID/a/c.html/lysosomal_disorders/disorders_glycoprotein_degradation_mannosidosis_mannosidosis_fucosidosis_sialidosis/abstract
4. Barlow JJ, DiCioccio RA, Dillard PH, et al: Frequency of an allele for low activity of alpha-L-fucosidase in sera: possible increase in epithelial ovarian cancer patients. J Natl Cancer Inst 1981 Nov; 67(5):1005-1009
Method Description Describes how the test is performed and provides a method-specific reference
Incubation of 4-methylumbelliferyl-alpha-L-fucopyranoside with cell homogenates results in cleavage of the substrate by alpha-L-fucosidase yielding 4-methylumbelliferone (4-MU) and fucose. Free 4-MU can be quantitated by measurement of the fluorescence.(Beratis NG, Turner BM, Labadie G, Hirschhorn K: a-L-fucosidase in cultured skin fibroblasts from normal subjects and fucosidosis patients. Pediatr Res 1977;11:862-866)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Specimens are processed Monday through Sunday. Assay is performed on Wednesday; 8 a.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
WBC homogenate stored 1 month
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
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 Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|35635||Interpretation (FUCW)||In Process|
|35634||Reviewed By||In Process|