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HelpTest Code HEX4 Glucotetrasaccharides, Random, Urine
Ordering Guidance
Additional Testing Requirements
When requested for the diagnosis of Pompe disease (glycogen storage disorder type II), urine glucotetrasaccharide concentrations need to be interpreted in light of the clinical presentation and other laboratory test results, such as blood creatine kinase, alpha-glucosidase (GAA) activity, and GAA genotype.
Necessary Information
1. Patient's age is required.
2. Reason for testing is required.
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube: Plastic, 5-mL urine tube
Specimen Volume: 3 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Useful For
Diagnosing Pompe disease, when used in conjunction with acid alpha-glucosidase enzyme activity assays and molecular genetic analysis of the GAA gene
Monitoring patients with Pompe disease on enzyme replacement therapy
May support the diagnosis and monitoring of other glycogen storage disorders; however, glucotetrasaccharide (Glc4) excretion appears to be less consistently elevated in glycogen storage disorders other than Pompe disease
This test is not useful for carrier screening.
Testing Algorithm
For more information see Newborn Screen Follow-up for Pompe Disease
Special Instructions
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Glucotetrasaccharides, USpecimen Type
UrineSpecimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Frozen (preferred) | 87 days | |
| Refrigerated | 28 days | ||
| Ambient | 14 days |
Reference Values
≤14 months: ≤14.9 mmol/mol Cr
≥15 months: ≤4.0 mmol/mol Cr
Interpretation
An elevated excretion of glucotetrasaccharide is indicative of Pompe disease or other glycogen storage disorders.
Enzyme or molecular analysis is required to confirm suspected diagnosis.
Clinical Reference
1. Sluiter W, van den Bosch JC, Goudriann DA, et al. Rapid ultraperformance liquid chromatography-tandem mass spectrometry assay for a characteristic glycogen-derived tetrasaccharide in Pompe disease and other glycogen storage diseases. Clin Chem. 2012;58(7):1139-1147
2. Young S, Stevens RD, An Y, et al. Analysis of a glucose tetrasaccharide elevated in Pompe disease by stable isotope dilution–electrospray ionization tandem mass spectrometry. Anal Biochem. 2003;316(2):175-180
3. Chien YH, Goldstein JL, Hwu WL, et al. Baseline urinary glucose tetrasaccharide concentrations in patients with infantile- and late-onset Pompe disease identified by newborn screening. JIMD Rep. 2015;19:67-73
4. Young SP, Piraud M, Goldstein, JL, et al. Assessing disease severity in Pompe disease: the roles of a urinary glucose tetrasaccharide biomarker and imaging techniques. Am J Med Genet C Semin Med Genet. 2012;160C(1):50-58
5. Morales-Vila A, Corbalan-Rivas A, Carnero-Gregorio M, et al. Biomarkers in glycogen storage diseases: an update. Int. J Mol Sci. 2021;22(9):4381. doi:10.3390/ijms22094381
Day(s) Performed
Wednesday
Report Available
4 to 10 daysPerforming 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
82542
82570
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| HEX4 | Glucotetrasaccharides, U | 53868-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 64174 | Glucotetrasaccharides, U | 53868-6 |
| BG710 | Reason for Referral | 42349-1 |
| BA2896 | Intepretation (HEX4) | 59462-2 |
| BA2897 | Reviewed By | 18771-6 |