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Test Code IDUAW Alpha-L-Iduronidase, Leukocytes


Ordering Guidance


This test is preferred for diagnostic testing. For carrier detection, order IDUA / Mucopolysaccharidosis Type I, IDUA Gene Sequencing with Deletion/Duplication, Varies.



Shipping Instructions


For optimal isolation of leukocytes, it is recommended the specimen arrives refrigerated within 6 days 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) or lavender top (EDTA)

Specimen Volume: 6 mL

Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.


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.

Useful For

Diagnosis of mucopolysaccharidosis I, Hurler, Scheie, and Hurler-Scheie syndromes in leukocytes

 

This test is not useful for determining carrier status.

Method Name

Flow Injection Analysis-Tandem Mass Spectrometry (FIA-MS/MS)

Reporting Name

Alpha-L-Iduronidase, Leukocytes

Specimen Type

Whole Blood ACD

Specimen Minimum Volume

4 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole Blood ACD Refrigerated (preferred) 6 days
  Ambient  6 days

Reference Values

≥2.06 nmol/hour/mg protein

An interpretive report will be provided.

Interpretation

Results below 2.06 nmol/hour/mg protein in properly submitted specimens are consistent with alpha-L-iduronidase deficiency (mucopolysaccharidosis I). Further differentiation between Hurler, Scheie, and Hurler-Scheie syndromes is dependent upon the clinical findings.

 

Normal results (≥2.06 nmol/hour/mg protein) are not consistent with alpha-L-iduronidase deficiency.

Clinical Reference

1. 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; 2023. Updated November 2023. Accessed July 22, 2025. Available at www.acmg.net/PDFLibrary/MPSI-ACT-Sheet.pdf

2. Clark LA, Atherton AM, Burton BK, et al. Mucopolysaccharidosis type I newborn screening: Best practices for diagnosis and management. J Pediatr. 2017;182:363-370

3. Martins AM, Dualibi AP, Norato D, et al. Guidelines for the management of mucopolysaccharidosis type I. J Pediatr. 2009:155(4 Suppl):S32-S46

4. Enns GM, Steiner RD, Cowan TM: Lysosomal disorders: mucopolysaccharidoses. In: Sarafoglou K, Hoffmann GF, Roth KS, eds. Pediatric Endocrinology and Inborn Errors of Metabolism. McGraw-Hill, Medical Publishing Division; 2009:721-730

5. Clarke LA: Mucopolysaccharidosis type I. In: Adam MP, Ardinger HH, Pagon RA, et al, eds. GeneReviews [Internet]. University of Washington, Seattle; 2002. Updated April 11, 2024. Accessed July 22, 2025. Available at www.ncbi.nlm.nih.gov/books/NBK1162/

6. Elliott S, Buroker N, Cournoyer JJ, et al. Pilot study of newborn screening for six lysosomal storage diseases using tandem mass spectrometry. Mol Genet Metab. 2016;118(4):304-309

Day(s) Performed

Preanalytical processing: Monday through Saturday.

Testing performed: Monday, Thursday

Report Available

2 to 5 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

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

82657

LOINC Code Information

Test ID Test Order Name Order LOINC Value
IDUAW Alpha-L-Iduronidase, Leukocytes 24057-2

 

Result ID Test Result Name Result LOINC Value
606276 Alpha-L-Iduronidase, Leukocytes 24057-2
606277 Interpretation 59462-2
606278 Reviewed By 18771-6