Test Catalog

Test Id : ANAS

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Alpha-N-Acetylglucosaminidase, Serum

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosis of Sanfilippo syndrome type B (mucopolysaccharidoses type IIIB)

 

This test is not suitable for carrier detection.

Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request

This test is used for the diagnosis of mucopolysaccharidoses (MPS) IIIB (Sanfilippo Syndrome type B) only.

 

Sanfilippo types A, C, and D must be ruled out independently.

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

Colorimetric

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Alpha-N-Acetylglucosaminidase, S

Aliases
Lists additional common names for a test, as an aid in searching

Acetylglucosaminidase, Alpha-N

MPS 3B

MPS IIIB

Mucopolysaccharidosis IIIB

N-Acetyl-Alpha-D-Glucosaminidase Deficiency

NAGLU Deficiency

Sanfilippo Syndrome B

Sanfilippo Syndrome Type B

Sanfilippo Type B

Alpha-N-acetylglucosaminidase

I-cell disease

Mucolipidosis II

Mucolipidosis III

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Specimen Type
Describes the specimen type validated for testing

Serum

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Special Instructions
Library of PDFs including pertinent information and forms related to the test

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

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

2. Biochemical Genetics Patient Information (T602)

3. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.8 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Frozen 365 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosis of Sanfilippo syndrome type B (mucopolysaccharidoses type IIIB)

 

This test is not suitable for carrier detection.

Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request

This test is used for the diagnosis of mucopolysaccharidoses (MPS) IIIB (Sanfilippo Syndrome type B) only.

 

Sanfilippo types A, C, and D must be ruled out independently.

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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 a deficiency of any of the enzymes involved in the stepwise degradation of dermatan sulfate, heparan sulfate, keratan sulfate, or chondroitin sulfate (glycosaminoglycans: GAG). 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 (MPS type III) is an autosomal recessive MPS with 4 recognized types (A-D). Each type is caused by a deficiency in 1 of 4 enzymes involved in the degradation of heparan sulfate resulting in its intra- and extra-cellular accumulation. Though biochemically different, the clinical presentation of all types is indistinguishable. Sanfilippo syndrome is characterized by severe central nervous system degeneration, but other symptoms seen in MPS, such as coarse facial features and skeletal involvement, tend to be milder. It is important to note the variability in severity for MPSIII. In some patients, only moderate intellectual disability can be observed even at the end of the third decade of life. However, 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, although individuals with an attenuated phenotype may have a longer life expectancy and remain functional into their third and fourth decades.

 

Sanfilippo syndrome type B is due to a deficiency of the enzyme N-acetyl-alpha-D-glucosaminidase (alpha-hexosaminidase), caused by variants in the NAGLU gene. Affected individuals demonstrate elevations of heparan sulfate in blood and urine (MPSBS / Mucopolysaccharidosis, Blood Spot and MPSQU / Mucopolysaccharides Quantitative, Random, Urine). Diagnostic sequencing and deletion/duplication studies of the NAGLU gene (CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies; specify NAGLU Gene List ID: IEMCP-KG2Q99) is available for patients with an enzyme deficiency.

 

Elevations in serum of alpha-N-acetylglucosaminidase and other hydrolases may be seen in patients with mucolipidosis II/III (I-cell disease).(1) I-cell disease is an autosomal recessive lysosomal storage disorder resulting in impaired transport and phosphorylation of newly synthesized lysosomal proteins to the lysosome due to deficiency of N-acetylglucosamine 1-phosphotransferase (GlcNAc). Characteristic clinical features include short stature, skeletal and cardiac abnormalities, and developmental delay. Measurement of alpha-N-acetylglucosaminidase activity is not the preferred diagnostic test for I-cell disease but may be included in the testing strategy.

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.

0.09-0.58 U/L

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

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.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Braulke T, Raas-Rothschild A, Kornfeld S: I-cell disease and pseudo-Hurler polydystrophy: Disorders of lysosomal enzyme phosphorylation and localization. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds: The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019. Accessed May 24, 2021. Available at https://ommbid.mhmedical.com/content.aspx?bookid=2709&sectionid=225544648

2. Joanna Jakobkiewicz-Banecka, Magdalena Gabig-Ciminska, Anna Kloska, et al. Glycosaminoglycans and mucopolysaccharidosis type III. Frontiers in Bioscience-Landmark. 2016 Jun. 21; 1393-1409.

3. Neufeld EF, Muenzer J: The mucopolysaccharidoses. In: Valle D, Beaudet AL, Vogelstein B, et al; eds. The Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019. Accessed May 24, 2021. Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225544161&bookid=2709

4. Valstar MJ, Bruggenwirth HT, Olmer R, et al: Mucopolysaccharidosis type IIIB may predominantly present with an attenuated clinical phenotype. J Inherit Metab Dis. 2010 Dec;33(6):759-767. doi: 10.1007/s10545-010-9199-y

5. Beneto N, Vilageliu L, Grinberg D, Canals I: Sanfilippo syndrome: Molecular basis, disease models and therapeutic approaches. Int J Mol Sci. 2020 Oct;21(21):7819. doi: 10.3390/ijms21217819

Special Instructions
Library of PDFs including pertinent information and forms related to the test

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 serum 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. doi: 10.1016/s0022-3476(73)80222-7; Cowan T, Pasquali M: Laboratory Investigations of inborn errors of metabolism. In: Sarafoglou K, Hoffman GF, Roth KS, eds: Pediatric Endocrinology and Inborn Errors of Metabolism. 2nd ed. McGraw-Hill; 2017:1139-1158)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Once per month

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

30 to 45 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 month

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

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 instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) 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 US 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 Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

84311

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
ANAS Alpha-N-Acetylglucosaminidase, S 1837-4
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
50564 Specimen 31208-2
50565 Specimen ID 57723-9
50566 Source 31208-2
50567 Order Date 82785-7
50568 Reason For Referral 42349-1
50569 Method 85069-3
50577 Alpha-N-Acetylglucosaminidase, S 1837-4
50570 Interpretation 59462-2
50571 Amendment 48767-8
50572 Reviewed By 18771-6
50573 Release Date 82772-5

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports