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Test Code GAAW Acid Alpha-Glucosidase, Leukocytes


Shipping Instructions


For optimal isolation of leukocytes, it is recommended the specimen arrive refrigerate 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 Pompe disease

Testing Algorithm

For testing algorithm information see Newborn Screen Follow-up for Pompe Disease.

For Newborn Screening ACT Sheet for Pompe Disease (Glycogen Storage Disease Type II) information, visit www.acmg.net/PDFLibrary/Pompe.pdf.

Method Name

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

Reporting Name

Acid Alpha-Glucosidase, Leukocytes

Specimen Type

Whole Blood ACD

Specimen Minimum Volume

2 mL

Specimen Stability Information

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

Reference Values

≥1.50 nmol/hour/mg protein

An interpretive report is provided.

Interpretation

When abnormal results are detected, a detailed interpretation is given, including an overview of the results and of their significance, a correlation to available clinical information, elements of differential diagnosis, recommendations for additional biochemical testing and in vitro, confirmatory studies (enzyme assay, molecular analysis), and a phone number to reach one of the laboratory directors in case the referring physician has additional questions.

Clinical Reference

1. 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 Aug;118(4):304-309. doi: 10.1016/j.ymgme.2016.05.015

2. Matern D, Gavrilov D, Oglesbee D, Raymond K, Rinaldo P, Tortorelli S: Newborn screening for lysosomal storage disorders. Semin Perinatol. 2015 Apr;39(3):206-216. doi: 10.1053/j.semperi.2015.03.005

3. Reuser AJJ, Hirschhorn R, Kroos MA: Pompe disease: Glycogen storage disease type II, acid a-glucosidase (acid maltase) deficiency. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA. eds. Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019. Accessed June 30, 2020. Available at https://ommbid.mhmedical.com/content.aspx?bookid=2709&sectionid=225890450

4. Lin N, Huang J, Violante S, et al: Liquid chromatography-tandem mass spectrometry assay of leukocyte acid alpha-glucosidase for post-newborn screening evaluation of Pompe disease. Clin Chem. 2017 Apr;63(4):842-851. doi: 10.1373/clinchem.2016.259036

5. Leslie N, Bailey L: Pompe disease. In: Adam MP, Ardinger HH, Pagon RA, et al. GeneReviews [Internet]. University of Washington, Seattle; 2007. Updated May 11, 2017. Accessed March 23, 2022. Available at www.ncbi.nlm.nih.gov/books/NBK1261/

Day(s) Performed

Preanalytical processing: Monday through Saturday.

Assay performed: Monday, Wednesday

Report Available

5 to 9 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
GAAW Acid Alpha-Glucosidase, Leukocytes 24051-5

 

Result ID Test Result Name Result LOINC Value
606267 Acid Alpha-Glucosidase, Leukocytes 24051-5
606268 Interpretation 59462-2
606269 Reviewed By 18771-6