Test Catalog

Test Id : MPS1R

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Endogenous Mucopolysaccharidosis Type I (IDUA [Alpha-L-Iduronidase]) Biomarker Reflex, Blood Spot

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Overview

Test Catalog

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

Second-tier testing of newborns with an abnormal primary screening result for mucopolysaccharidosis type I (MPS I, decreased alpha-L-iduronidase activity) where quantitation of the glycosaminoglycans dermatan and heparan sulfate is desired in the presence of elevated endogenous MPS I biomarkers

 

Follow-up testing for evaluation of an abnormal newborn screening result for MPS I

 

This test is not useful a monitoring test for individuals with MPS I.

 

This test is not appropriate 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 a second-tier assay for newborns and infants who have abnormal newborn screening results for mucopolysaccharidosis type I (MPS I) with reduced alpha-L-iduronidase activity.

Highlights

This assay provides an assessment of a glycosaminoglycan (GAG) fragment that is specific to mucopolysaccharidosis type I (MPS I) with reflex to quantitative values of heparan, dermatan, and keratan sulfate when elevated.

 

Elevations of the MPS I specific endogenous biomarker and the GAGs heparan and dermatan sulfate are suggestive of a diagnosis of MPS I.

 

This assay can help differentiate true cases of MPS I from false-positive cases (such as carriers and pseudodeficiency of alpha-L-iduronidase enzyme).

 

Additional biochemical or molecular testing is required to confirm a diagnosis of MPS I.

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test Id Reporting Name Available Separately Always Performed
MPSBS Mucopolysaccharidosis, BS Yes No

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

Testing begins with analysis of the mucopolysaccharidosis type I (MPS I) specific endogenous biomarker. If it is within the normal range, testing is complete. If the MPS I specific endogenous biomarker is elevated, quantification of heparan sulfate, dermatan sulfate, and keratan sulfate will be performed at an additional charge.

 

If the patient has abnormal newborn screening results for MPS I, timely action should be taken. Refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)

 

For more information see Newborn Screen Follow-up for Mucopolysaccharidosis Type I.

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

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

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

MPS I Biomarker Reflex, BS

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

Alpha-L-Iduronidase deficiency

Attenuated MPS I

Glycosaminoglycan biomarker

Hurler syndrome (MPS IH)

Hurler-Scheie syndrome (MPS IH/S)

IDUA deficiency

Mucopolysaccharidosis type I (MPS I)

Non-reducing ends

NRE

Scheie syndrome (MPS IS)

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

Testing begins with analysis of the mucopolysaccharidosis type I (MPS I) specific endogenous biomarker. If it is within the normal range, testing is complete. If the MPS I specific endogenous biomarker is elevated, quantification of heparan sulfate, dermatan sulfate, and keratan sulfate will be performed at an additional charge.

 

If the patient has abnormal newborn screening results for MPS I, timely action should be taken. Refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)

 

For more information see Newborn Screen Follow-up for Mucopolysaccharidosis Type I.

Specimen Type
Describes the specimen type validated for testing

Whole blood

Ordering Guidance

This test is recommended for assessment of newborns and infants with a positive newborn screen (reduced IDUA activity) for mucopolysaccharidosis type I (MPS I). This test is not intended to be used as a monitoring test for individuals with confirmed MPS I.

Shipping Instructions

Specimens stored at ambient temperatures for more than 13 days after collection may result in false-positive results in carrier and other unaffected individuals.

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

Supplies: Card-Blood Spot Collection (Filter Paper) (T493)

Container/Tube:

Preferred: Blood Spot Collection Card

Acceptable: Whatman Protein Saver 903 paper, PerkinElmer 226 filter paper, Munktell filter paper, local newborn screening card, postmortem screening card, or blood collected in tubes containing ACD or EDTA and dried on filter paper.

Specimen Volume: 2 Blood spots

Collection Instructions:

1. An alternative blood collection option for a patient older than 1 year is a fingerstick. For detailed instructions, see How to Collect Dried Blood Spot Samples.

2. Completely fill at least 2 circles on filter paper card (approximately 100 microliters blood per circle).

3. Let blood dry on the filter paper at ambient temperature in a horizontal position for a minimum of 3 hours.

4. Do not expose specimen to heat or direct sunlight.

5. Do not stack wet specimens.

6. Keep specimen dry.

Additional Information:

1. For collection instructions, see Blood Spot Collection Instructions

2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777)

3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800)

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

Forms

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

1 Blood spot

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

Blood spot specimen that shows serum rings or has multiple layers/applications Reject

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
Whole blood Refrigerated (preferred) 30 days FILTER PAPER
Frozen 90 days FILTER PAPER
Ambient 13 days FILTER PAPER

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

Second-tier testing of newborns with an abnormal primary screening result for mucopolysaccharidosis type I (MPS I, decreased alpha-L-iduronidase activity) where quantitation of the glycosaminoglycans dermatan and heparan sulfate is desired in the presence of elevated endogenous MPS I biomarkers

 

Follow-up testing for evaluation of an abnormal newborn screening result for MPS I

 

This test is not useful a monitoring test for individuals with MPS I.

 

This test is not appropriate 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 a second-tier assay for newborns and infants who have abnormal newborn screening results for mucopolysaccharidosis type I (MPS I) with reduced alpha-L-iduronidase activity.

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

Testing begins with analysis of the mucopolysaccharidosis type I (MPS I) specific endogenous biomarker. If it is within the normal range, testing is complete. If the MPS I specific endogenous biomarker is elevated, quantification of heparan sulfate, dermatan sulfate, and keratan sulfate will be performed at an additional charge.

 

If the patient has abnormal newborn screening results for MPS I, timely action should be taken. Refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)

 

For more information see Newborn Screen Follow-up for Mucopolysaccharidosis Type I.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Mucopolysaccharidosis type I (MPS I) is an autosomal recessive disorder caused by reduced or absent activity of the enzyme alpha-L-iduronidase due to variants in the IDUA gene. Deficiency of alpha-L-iduronidase can result in a wide range of phenotypes categorized into 3 syndromes: Hurler syndrome (MPS IH), Scheie syndrome (MPS IS), and Hurler-Scheie syndrome (MPS IH/S). Because these syndromes cannot be distinguished biochemically, they are also referred to as MPS I and attenuated MPS I.

 

Clinical features and severity of symptoms of MPS I are variable, ranging from severe disease to an attenuated form that generally presents at a later onset with a milder clinical presentation. In general, symptoms may include coarse facies, progressive dysostosis multiplex, hepatosplenomegaly, corneal clouding, hearing loss, intellectual disabilities or learning difficulties, and cardiac valvular disease. The incidence of MPS I is approximately 1 in 100,000 live births. Treatment options include hematopoietic stem cell transplantation and enzyme replacement therapy.

 

Individuals with MPS I typically demonstrate elevated levels of the glycosaminoglycans (GAGs) dermatan sulfate and heparan sulfate (see MPSQU / Mucopolysaccharides Quantitative, Random, Urine; MPSBS / Mucopolysaccharides, Blood Spot), as well as elevated levels of GAG fragments known as endogenous disaccharide biomarkers that are specific to the deficiency of alpha-L-iduronidase. Reduced or absent activity of alpha L-iduronidase (see IDUAW / Alpha-L-Iduronidase, Leukocytes) can confirm a diagnosis of MPS I but may also be deficient in unaffected individuals who are carriers or with pseudodeficiency. Molecular sequence analysis of the IDUA gene allows for detection of disease-causing variants in affected individuals and subsequent carrier detection in relatives (see MPS1Z / Hurler Syndrome, Full Gene Analysis, Varies).

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.

An interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

The measurements of mucopolysaccharidosis type I (MPS I) specific endogenous biomarker is compared to the reference value. This report is in text form only, indicating if the MPS I specific endogenous biomarker value is or is not suggestive of a biochemical diagnosis of MPS I. In any specimen where the MPS I specific endogenous biomarker value is elevated, quantitative analysis of heparan, dermatan, and keratan sulfate will be performed. Abnormal results are not sufficient to conclusively establish a diagnosis of a particular disease. To verify a preliminary diagnosis, independent biochemical (ie, in vitro enzyme assay and quantitative glycosaminoglycan measurement) or molecular genetic analyses are required, many of which are offered within Mayo Clinic Laboratories. Recommendations for additional biochemical testing and confirmatory studies (biomarker, enzyme assay, molecular analysis) are provided in the interpretative report.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

No significant cautionary statements

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

1. ACMG Newborn Screening ACT Sheets. Newborn Screening ACT Sheet [alpha-L-iduronidase deficiency with or without glycosaminoglycan (GAG) accumulation] Mucopolysaccharidosis Type I (MPS I). American College of Medical Genetics and Genomics; 2022. Updated November 2023. Accessed October 23, 2024. Available at www.acmg.net/PDFLibrary/MPS-II.pdf

2. Saville JT, Herbst ZM, Gelb MH, Fuller M. Endogenous, non-reducing end glycosaminoglycan biomarkers for the mucopolysaccharidoses: Accurate diagnosis and elimination of false positive newborn screening results. Mol Gen Metab. 2023;140(3):107685

3. Herbst ZM, Hong X, Urdaneta L, et al. Endogenous, non-reducing end glycosaminoglycan biomarkers are superior to internal disaccharide glycosaminoglycan biomarkers for newborn screening of mucopolysaccharidoses and GM1 gangliosidosis. Mol Genet Metab. 2023;140(1-2):107632

4. Peck DS, Lacey JM, White AL, et al. Incorporation of second-tier biomarker testing improves the specificity of newborn screening for mucopolysaccharidosis type I. Int J Neonatal Screen. 2020;6(1):10. doi:10.3390/ijns6010010

Method Description
Describes how the test is performed and provides a method-specific reference

Sample preparation consists of extraction from dried blood spots using aqueous buffer and the addition of reagents to aid in removing the analytes from the filter paper. The resulting extracted analytes are chemically derived to aid in chromatographic separation and to increase signal intensity. A liquid/liquid extraction is preformed to remove the derived analytes from bulk matrix. The sample is then analyzed via liquid chromatography tandem mass spectrometry.(Unpublished Mayo method)

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.

Monday, Thursday

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.

3 to 6 days

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

6 months

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 account representative. 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. It 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.

82542

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
MPS1R MPS I Biomarker Reflex, BS In Process
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.
622361 Interpretation 59462-2
622362 Reviewed by 18771-6

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

Test Update Resources

Change Type Effective Date
New Test 2025-01-07