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HelpMayo Test ID AGU20 Acylglycines, Quantitative, Random, Urine
Additional Testing Requirements
Diagnostic specificity of inborn errors of metabolism via urine acylglycine testing is available only for selected inborn errors of metabolism; it is recommended that urine organic acids (OAU / Organic Acids Screen, Random, Urine) be ordered and assessed simultaneously due to the limited number of metabolites included in this urine acylglycine test.
Necessary Information
1. Patient's age and sex are required.
2. Include family history, clinical condition (asymptomatic or acute episode), diet, and drug therapy information
Specimen Required
Supplies: Urine Tubes, 10 mL (T068)
Container/Tube: Plastic, 10-mL urine tube
Specimen Volume: 10 mL
Pediatric: If insufficient collection volume, submit as much specimen as possible in a single container; the laboratory will determine if volume is sufficient for testing.
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
Useful For
Diagnosis and monitoring for patients affected with one of the following inborn errors of metabolism:
Fatty Acid Oxidation Disorders:
-Glutaric acidemia type II
-Medium-chain 3-ketoacyl-coenzyme A (CoA) thiolase (MCKAT) deficiency
-Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency
-Short chain acyl-CoA dehydrogenase (SCAD) deficiency
Organic Acidurias:
-2-Methyl-3-hydroxybutyryl-CoA dehydrogenase (2M3HBD) deficiency
-2-Methylbutyryl-CoA dehydrogenase deficiency
-3-Methylcrotonyl-CoA carboxylase deficiency
-3-Methylglutaconyl-CoA-hydratase deficiency
-Aminoacylase 1 deficiency
-Beta-ketothiolase deficiency
-Ethylmalonic encephalopathy
-Glutaryl-CoA dehydrogenase deficiency
-Isobutyryl-CoA dehydrogenase deficiency
-Isovaleryl-CoA dehydrogenase deficiency
-Multiple carboxylase deficiency
-Propionic acidemia
Special Instructions
Method Name
Gas Chromatography Mass Spectrometry (GC-MS)
Reporting Name
Acylglycines, QN, USpecimen Type
UrineSpecimen Minimum Volume
4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Frozen (preferred) | 416 days | |
| Refrigerated | 9 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Clinical Information
Acylglycines are glycine conjugates of acyl-coenzyme A species, which occur as normal intermediates of amino acid and fatty acid metabolism. In abnormal concentrations, acylglycines are biochemical markers of selected inborn errors of metabolism. Analysis of acylglycines is useful for the diagnosis and monitoring for specific fatty acid oxidation disorders and organic acidurias; however, it is recommended to use this testing in conjunction with urine organic acids and plasma acylcarnitines testing in order to establish a diagnosis.
In particular, acylglycine analysis is more sensitive and specific for the identification of asymptomatic patients and those who may experience mild or intermittent biochemical phenotypes that could be missed by organic acid analysis alone.
Reference Values
n-Acetylglycine:≤3.50 mg/g Creatinine
n-Propionylglycine:≤2.25 mg/g Creatinine
Isobutyrylglycine:≤3.00 mg/g Creatinine
Ethylmalonic acid:≤25.00 mg/g Creatinine
n-Butyrylglycine:≤2.50 mg/g Creatinine
2-Methylsuccinic acid:≤9.00 mg/g Creatinine
2-Methylbutyrylglycine:≤2.00 mg/g Creatinine
Isovalerylglycine:≤8.00 mg/g Creatinine
Glutaric acid:≤8.00 mg/g Creatinine
3-Methylcrotonylglycine:≤2.25 mg/g Creatinine
n-Tiglylglycine:≤9.00 mg/g Creatinine
3-Methylglutaconic acid:≤25.00 mg/g Creatinine
n-Hexanoylglycine:≤2.00 mg/g Creatinine
n-Octanoylglycine:≤2.00 mg/g Creatinine
3-Phenylpropionylglycine:≤2.00 mg/g Creatinine
trans-Cinnamoylglycine:≤5.50 mg/g Creatinine
Suberylglycine:≤5.00 mg/g Creatinine
Dodecanedioic acid:≤0.50 mg/g Creatinine
Tetradecanedioic acid:≤0.50 mg/g Creatinine
Hexadecanedioic acid:≤0.50 mg/g Creatinine
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); name and phone number of key contacts who may provide these studies at Mayo Clinic or elsewhere; and a phone number to reach one of the laboratory directors in case the referring physician has additional questions.
Cautions
No significant cautionary statements
Clinical Reference
1. Rinaldo P, Hahn SH, Matern D. Inborn errors of amino acid, organic acid, and fatty acid metabolism. In: Burtis CA, Ashwood ER, Bruns DE eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 4th ed. WB Saunders Company; 2005:2207-2247
2. Roe CR, Ding J. Mitochondrial fatty acid oxidation disorders. In: Valle D, Antonarakis S, Ballabio A, Beaudet A, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019. Accessed March 21, 2024. http://ommbid.mhmedical.com/content.aspx?bookid=2709§ionid=225087274
3. Kolker S, Cazorla AG, Valayannopoulos V, et al. The phenotypic spectrum of organic acidurias and urea cycle disorders. Part 1: the initial presentation. J Inherit Metab Dis. 2015;38(6):1041-1057. doi:10.1007/s10545-015-9839-3
4. Tuncel AT, Boy N, Morath MA, Horster F, Mutze U, Kolker S. Organic acidurias in adults: late complications and management. J Inherit Metab Dis. 2018;41(5):765-776. doi:10.1007/s10545-017-0135-2
5. Pasquali M, Longo N. Newborn screening and inborn errors of metabolism. In: Rifai N, Chiu, RWK, Young I, Burnham CD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 60
Method Description
Urine volumes equivalent to 0.25 to 0.50 mg of creatinine are spiked with the mixture of labeled internal standards, allowed to equilibrate, acidified, and then extracted. After evaporation, the dry residue is derivatized to butyl esters. Specimens are analyzed by capillary gas chromatography mass spectrometry selected ion monitoring using ammonia chemical ionization and a stable isotope dilution method.(Unpublished Mayo method)
Specimen Retention Time
3 monthsPerforming 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
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| AGU20 | Acylglycines, QN, U | 50334-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 608931 | Interpretation | 53718-3 |
| 608910 | n-Acetylglycine | 99059-8 |
| 608911 | n-Propionylglycine | 13800-8 |
| 608912 | Isobutyrylglycine | 38360-4 |
| 608913 | Ethylmalonic acid | 13741-4 |
| 608914 | n-Butyrylglycine | 27892-9 |
| 608915 | 2-Methylsuccinic acid | 13777-8 |
| 608916 | 2-Methylbutyrylglycine | 27097-5 |
| 608917 | Isovalerylglycine | 13766-1 |
| 608918 | Glutaric acid | 13748-9 |
| 608919 | 3-Methylcrotonylglycine | 13691-1 |
| 608920 | n-Tiglylglycine | 13816-4 |
| 608921 | 3-Methylglutaconic acid | 13692-9 |
| 608922 | n-Hexanoylglycine | 13753-9 |
| 608923 | n-Octanoylglycine | 38367-9 |
| 608924 | 3-Phenylpropionylglycine | 13793-5 |
| 608925 | trans-Cinnamoylglycine | 38417-2 |
| 608926 | Suberylglycine | 13811-5 |
| 608927 | Dodecanedioic acid | 13732-3 |
| 608928 | Tetradecanedioic acid | 50333-4 |
| 608929 | Hexadecanedioic acid | 50332-6 |
| 608930 | Reviewed By | 18771-6 |
Day(s) Performed
Monday, Thursday
Report Available
3 to 6 daysTesting Algorithm
For more information see Newborn Screen Follow-up for Elevated C5-OH.