Test ID: ANAT
Alpha-N-Acetylglucosaminidase, Fibroblasts
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Diagnosis of Sanfilippo syndrome, type B (mucopolysaccharidoses, type IIIB)
Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request
Diagnostic enzyme assay for Sanfilippo syndrome, type B.
Additional Tests Lists test(s) that are always performed, at an additional charge, with the initial test(s)
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| FIBR | Fibroblast Culture | Yes | Yes |
| CRYOB | Cryopreserve for Biochem Studies | No | Yes |
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, a fibroblast culture and cryopreservation for biochemical studies will always be performed at an additional charge. However, for multiple lysosomal enzyme assays on a patient utilizing fibroblast culture, only 1 culture is required regardless of the number of enzyme assays ordered. If viable cells are not obtained within 10 days, client will be notified.
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
Method Name A short description of the method used to perform the test
ANAT/8783: Colorimetric Enzyme Assay
FIBR/8482: Cultivated from Biopsy as Monolayer
CRYOB/88832: Fibroblast Subculture Followed by Cryopreservation and Storage
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
MPS 3B
MPS IIIB
Mucopolysaccharidosis IIIB
N-Acetyl-Alpha-D-Glucosaminidase Deficiency
NAGLU Deficiency
Sanfilippo Syndrome B
Sanfilippo Syndrome Type B
Sanfilippo Type B
Specimen Type Describes the specimen type needed for testing
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.
This test is not available for prenatal testing.
Forms:
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.
Submit only 1 of the following specimens:
Specimen Type: Cultured fibroblasts
Container/Tube: T-75 or T-25 flask
Specimen Volume: 1 full T-75 flask or 2 full T-25 flasks
Specimen Stability Information: Ambient (preferred)/Refrigerated <24 hours
Specimen Type: Skin biopsy
Container/Tube: Sterile container with any standard cell culture media (eg, minimal essential media, RPMI 1640). The solution should be supplemented with 1% penicillin and streptomycin. Tubes supplied upon request (Eagle's minimum essential medium with 1% penicillin and streptomycin [Supply T115]).
Specimen Volume: 4-mm punch
Specimen Stability Information: Refrigerated (preferred)/Ambient
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | Specimen in formalin or fixative preservative |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Tissue | Varies | |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The mucopolysaccharidoses (MPS) are a group of disorders caused by the deficiency of any of the enzymes involved in the stepwise degradation of dermatan sulfate, heparan sulfate, keratan sulfate, or chondroitin sulfate (glycosaminoglycans or GAG). Undegraded or partially degraded GAG (also called mucopolysaccharides or MPS) are stored in lysosomes or are excreted in the urine. Accumulation of GAG in lysosomes interferes with normal functioning of cells, tissues, and organs, resulting in the clinical features observed in MPS disorders.
Sanfilippo syndrome is a MPS with 4 recognized types (types A-D) caused by different enzyme deficiencies; the clinical presentation of all types, however, is indistinguishable. Sanfilippo syndrome is characterized by severe central nervous system (CNS) degeneration, but other symptoms seen in MPS, such as coarse facial features, tend to be milder. Such disproportionate involvement of the CNS is unique among the MPS. Onset of clinical features usually occurs between 2 and 6 years in a child who previously appeared normal. The presenting symptoms are most commonly developmental delay and severe behavioral problems. Severe neurologic degeneration occurs in most patients by 6 to 10 years of age, accompanied by a rapid deterioration of social and adaptive skills. Death generally occurs by age 20, though individuals with an attenuated phenotype may have a longer life expectancy. Although there is no cure for Sanfilippo syndrome, research of therapies has included bone marrow transplantation, enzyme replacement, and gene replacement.
Sanfilippo syndrome type B is due to the absence of the enzyme N-acetyl-alpha-D-glucosaminidase (alpha-hexosaminidase), caused by mutations in the NAGLU gene. Diagnostic sequencing of the NAGLU coding region and deletion/duplication studies are available for patients with an enzyme deficiency. Refer to www.genetests.org for a listing of laboratories currently offering this testing.
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.
0.076-0.291 U/g of cellular protein
Interpretation Provides information to assist in interpretation of the test results
Deficiency of alpha-N-acetylglucosaminidase is diagnostic for Sanfilippo syndrome type B.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
The preferred specimen type for diagnosing Sanfilippo syndrome type B is serum (ANAS/8782 Alpha-N-Acetylglucosaminidase, Serum); however, if fibroblasts are readily available, this test can also be used to diagnose this disorder.
This assay detects Sanfilippo syndrome type B only. The 3 other types of Sanfilippo syndrome (A, C, and D) must be ruled out independently.
This assay will not identify carrier status for Sanfilippo syndrome type B.
Interfering factors include lack of viable cells, bacterial contamination, failure to transport tissue in an appropriate media, excessive transport time, and exposure of the specimen to temperature extremes (freezing or >30 degrees C).
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Heron B, Mikaeloff Y, Froissart R, et al: Incidence and natural history of mucopolysaccharidosis type III in France and comparison with United Kindgom and Greece. Am J Med Genet A 2011;155A(1):58-68
2. Neufeld EF, Muenzer J: The mucopolysaccharidoses. In The Metabolic and Molecular Bases of Inherited Disease. 8th edition. Edited by CR Scriver, AL Beaudet, D Valle, et al. New York, McGraw-Hill Book Company, 2001, pp 3421-3452
3. Valstar MJ, Bruggenwirth HT, Olmer R, et al: Mucopolysaccharidosis type IIIB may predominantly present with an attenuated clinical phenotype. J Inherit Metab Dis 2010;33:759-767
Method Description Describes how the test is performed and provides a method-specific reference
When p-nitrophenol alpha-D-glucosaminide is used as substrate, it is hydrolyzed by fibroblast N-acetyl-alpha-D-glucosaminidase to yield p-nitrophenol and free N-acetyl-glucosamine. p-Nitrophenol is subsequently measured spectrophotometrically at a basic pH. (von Figura K, Logering M, Mersmann G, Kress H: Sanfilippo B disease: serum assays for detection of homozygous and heterozygous individuals in three families. J Pediatr 1973;83:607-611)
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.
Varies
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
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.
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.
82657-Alpha-N-acetylglucosaminidase
88233-Fibroblast culture
88240-Cryopreservation for biochemical studies
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 |
|---|---|---|
| 29780 | Specimen | 31208-2 |
| 29781 | Specimen ID | N/A |
| 29782 | Source | N/A |
| 29783 | Order Date | N/A |
| 29784 | Reason For Referral | 42349-1 |
| 29785 | Method | In Process |
| 29895 | A-N-Acetylglucosaminidase | 24091-1 |
| 29786 | Interpretation | 59462-2 |
| 29787 | Amendment | In Process |
| 29788 | Reviewed By | N/A |
| 29789 | Released Date | N/A |
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