Sign in →

Test Code LAB20910 Amino Acids, Quantitative, Random, Urine

Reporting Name

Amino Acids, QN, Random, U

Useful For

Evaluating patients with possible inborn errors of metabolism using random urine specimens

 

May aid in evaluation of endocrine disorders, liver diseases, muscle diseases, neoplastic diseases, neurological disorders, nutritional disturbances, kidney failure, and burns

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Urine


Additional Testing Requirements


Not all patients with homocystinuria will be detected by this assay. If homocystinuria is a concern, order CMMPP / Cobalamin, Methionine, and Methylmalonic Acid Pathways, Plasma or HCYSP / Homocysteine, Total, Plasma or HCYSS / Homocysteine, Total, Serum in tandem with this test.



Necessary Information


1. Patient's age is required.

2. Include family history, clinical condition (asymptomatic or acute episode), diet, and drug therapy information.

3. If prolidase deficiency is a concern, indicate on the amino acid order "Pretreat with acid hydrolysis prior to analysis". The acid hydrolysis will break up in vitro proline and hydroxyproline containing dipeptides, which are cleaved in vivo by prolidase.



Specimen Required


Supplies: Urine Tubes, 10 mL (T068)

Specimen Volume: 2 mL

Collection Instructions: Collect a random urine specimen.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen (preferred) 70 days
  Refrigerated  14 days

Reference Values

Amino Acid

Age groups

< 2 months

2-35 months

3-6 years

7-17 years

≥18 years

Taurine

Tau

<9026

<5604

<3680

<3954

<2134

Asparagine

Asn

<687

<1159

<238

<322

<204

Serine

Ser

<3202

<2741

<1386

<1116

<658

Hydroxyproline

Hyp

<2254

<1775

<89

<42

<48

Glycine

Gly

<13336

<9872

<4997

<4467

<4068

Glutamine

Gln

<2931

<3681

<1124

<1038

<764

Aspartic Acid

Asp

<290

<72

<46

<13

<12

Ethanolamine

EtN

<1589

<1765

<776

<536

<500

Histidine

His

<3806

<4578

<2596

<2294

<1508

Threonine

Thr

<1930

<1769

<496

<575

<384

Citrulline

Cit

<61

<67

<23

<17

<34

Sarcosine

Sar

<177

<52

<6

<10

<6

Beta-Alanine

bAla

<174

<79

<99

<139

<58

Alanine

Ala

<2856

<2360

<961

<794

<472

Glutamic Acid

Glu

<281

<210

<127

<63

<62

1-Methylhistidine

1MHis

<493

<470

<517

<453

<265

3-Methylhistidine

3MHis

<196

<662

<3346

<2027

<1920

Argininosuccinic Acid

Asa

<96

<103

<65

<57

<37

Homocitrulline

Hcit

<164

<169

<110

<107

<87

Arginine

Arg

<250

<147

<81

<42

<65

Alpha-aminoadipic Acid

Aad

<264

<397

<349

<138

<73

Gamma Amino-n-butyric Acid

GABA

<8

<14

<4

<3

<4

Beta-aminoisobutyric Acid

bAib

<2214

<2488

<840

<251

<265

Alpha-amino-n-butyric Acid

Abu

<58

<44

<37

<29

<19

Hydroxylysine

Hyl

<101

<87

<44

<22

<16

Proline

Pro

<1776

<1028

<29

<42

<98

Ornithine

Orn

<344

<238

<228

<291

<193

Cystathionine

Cth

<118

<53

<23

<24

<33

Cystine

Cys

<486

<285

<111

<84

<142

Lysine

Lys

<2217

<1321

<814

<463

<295

Methionine

Met

<76

<45

<24

<22

<15

Valine

Val

<308

<258

<119

<91

<73

Tyrosine

Tyr

<453

<603

<289

<371

<155

Isoleucine

Ile

<99

<131

<52

<29

<26

Leucine

Leu

<286

<215

<87

<70

<64

Phenylalanine

Phe

<342

<306

<178

<123

<98

Tryptophan

Trp

<241

<329

<222

<218

<140

Allo-isoleucine

AlloIle

<3

<6

<1

<2

<4

 

All results reported as nmol/mg creatinine.

Day(s) Performed

Monday through Friday

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

82139

LOINC Code Information

Test ID Test Order Name Order LOINC Value
AAPD Amino Acids, QN, Random, U 35087-6

 

Result ID Test Result Name Result LOINC Value
3481 Interpretation (AAPD) 49248-8
3452 Taurine 28595-7
3456 Asparagine 28603-9
3455 Serine 30058-2
34477 Hydroxyproline 28601-3
3460 Glycine 30066-5
3457 Glutamine 30056-6
34478 Aspartic Acid 30061-6
34479 Ethanolamine 28605-4
3477 Histidine 30047-5
3454 Threonine 30057-4
3459 Citrulline 30161-4
34480 Sarcosine 28610-4
3472 Beta-alanine 28588-2
3461 Alanine 30068-1
3458 Glutamic Acid 30059-0
3476 1-Methylhistidine 28606-2
3478 3-Methylhistidine 28594-0
34481 Argininosuccinic Acid 32229-7
34483 Homocitrulline 32248-7
3480 Arginine 30062-4
3462 Alpha-aminoadipic Acid 28598-1
34484 Gamma-amino-n-butyric Acid 28593-2
3473 Beta-aminoisobutyric Acid 28602-1
3463 Alpha-amino-n-butyric Acid 28590-8
34485 Hydroxylysine 30050-9
3483 Proline 30067-3
3474 Ornithine 30049-1
3466 Cystathionine 28599-9
3465 Cystine 30065-7
3475 Lysine 30048-3
3467 Methionine 30063-2
3464 Valine 30064-0
3470 Tyrosine 30054-1
3468 Isoleucine 30052-5
3469 Leucine 30053-3
3471 Phenylalanine 30055-8
34486 Tryptophan 28608-8
34487 Allo-isoleucine 73908-6
113130 Reviewed By 18771-6

Clinical Information

Amino acids are the basic structural units that comprise proteins and are found throughout the body. Many inborn errors of amino acid metabolism that affect amino acid transport or metabolism have been identified, such as phenylketonuria and tyrosinemia. Amino acid disorders can manifest at any age, but most become evident in infancy or early childhood. These disorders result in the accumulation or the deficiency of 1 or more amino acids in biological fluids, which leads to the clinical signs and symptoms of the specific amino acid disorder.

 

The clinical presentation is dependent upon the specific amino acid disorder. In general, affected patients may experience failure to thrive, neurologic symptoms, digestive problems, dermatologic findings, and physical and cognitive delays. If not diagnosed and treated promptly, amino acid disorders can result in intellectual disabilities and, possibly, death.

 

In addition, amino acid analysis may have clinical importance in the evaluation of several acquired conditions including endocrine disorders, liver diseases, muscle diseases, neoplastic diseases, neurological disorders, nutritional disturbances, kidney failure, and burns. General elevations in urine amino acid levels, called aminoaciduria, can be seen in disorders with amino acid transport defects, such as lysinuric protein intolerance and Hartnup disease, as well as in conditions with renal tubular dysfunction including Lowe syndrome and Dent disease.

Interpretation

When no significant abnormalities are detected, a simple descriptive interpretation is provided. 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, and a phone number to reach one of the laboratory directors in case the referring physician has additional questions.

Method Description

Quantitative analysis of amino acids is performed by liquid chromatography-tandem mass spectrometry. Patient samples are combined with isotopically labeled internal standard. Following protein precipitation, the supernatant is subjected to hydrophilic-interaction liquid chromatography for the separation of isomers with MS/MS detection of the underivatized amino acids.(Unpublished Mayo method)

Report Available

3 to 5 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Testing Algorithm

Testing includes quantitation of the following amino acids: taurine, threonine, serine, asparagine, hydroxyproline, glutamic acid, glutamine, aspartic acid, ethanolamine, sarcosine, proline, glycine, alanine, citrulline, alpha-aminoadipic acid, alpha-amino-n-butyric acid, valine, cystine, cystathionine, methionine, isoleucine, leucine, tyrosine, phenylalanine, beta-alanine, beta-aminoisobutyric acid, ornithine, lysine, 1-methylhistidine, histidine, 3-methylhistidine, argininosuccinic acid, allo-isoleucine, homocitrulline, gamma-amino-n-butyric acid, hydroxylysine, tryptophan, and arginine.

Method Name

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

Portions of this test are covered by patents held by Quest Diagnostics