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Test Code 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

Method Name

Gas Chromatography Mass Spectrometry (GC-MS)

Reporting Name

Acylglycines, QN, U

Specimen Type

Urine

Specimen 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

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

82542

Day(s) Performed

Monday, Thursday

Report Available

3 to 6 days