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Epic Code LAB355 Amino Acids, Quantitative, Random, Urine

Additional Codes

Mayo Code: AAPD

Epic Code: LAB355

Interface Order Alias: 10652

Cerner code: 40

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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, renal failure, and burns

Specimen Type

Urine


Additional Testing Requirements


Not all patients with homocystinuria will be detected by this assay. If homocystinuria is a concern, order 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

Reject Due To

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

Day(s) Performed

Monday through Friday

Reference Values

Amino Acid

Age groups

≤12 months

13-35 months

3-6 years

7-8 years

9-17 years

≥18 years

Phosphoserine

PSer

<1

<1

<1

<1

<1

<1

Phosphoethanolamine

PEtN

15-341

33-342

19-164

12-118

<88

<48

Taurine

Tau

37-8300

64-3255

76-3519

50-2051

57-2235

24-1531

Asparagine

Asn

25-1000

62-884

28-412

38-396

22-283

25-238

Serine

Ser

18-4483

284-1959

179-1285

153-765

105-846

97-540

Hydroxyproline

Hyp

<2536

<89

<46

<19

<22

<15

Glycine

Gly

362-18614

627-6914

412-5705

449-4492

316-4249

229-2989

Glutamine

Gln

139-2985

263-2979

152-1325

164-1125

188-1365

93-686

Aspartic Acid

Asp

<64

<56

<30

<9

<11

<10

Ethanolamine

EtN

282-3782

256-947

193-643

137-564

158-596

95-471

Histidine

His

145-3833

427-3398

230-2635

268-2147

134-1983

81-1128

Threonine

Thr

25-1217

55-763

30-554

25-456

37-418

31-278

Citrulline

Cit

<72

<57

<14

<9

<14

<12

Sarcosine

Sar

<75

<12

<9

<2

<3

<3

Beta-Alanine

bAla

<219

<92

<25

<25

<49

<52

Alanine

Ala

93-3007

101-1500

64-1299

44-814

51-696

56-518

Glutamic Acid

Glu

<243

12-128

<76

<39

<62

<34

1-Methylhistidine

1MHis

17-419

18-1629

10-1476

19-1435

12-1549

23-1339

3-Methylhistidine

3MHis

88-350

86-330

56-316

77-260

47-262

70-246

Argininosuccinic Acid

Asa

<77

<48

<37

<24

<69

<15

Carnosine

Car

27-1021

16-616

18-319

<161

<109

<35

Anserine

Ans

<277

<820

<398

<141

<369

<38

Homocitrulline

Hcit

<295

11-158

<71

<62

<33

<30

Arginine

Arg

10-560

20-395

14-240

<134

<153

<114

Alpha-aminoadipic Acid

Aad

10-275

15-324

10-135

<84

<76

<47

Gamma Amino-n-butyric Acid

GABA

<25

<13

<11

<6

<5

<5

Beta-aminoisobutyric Acid

bAib

18-3137

<980

15-1039

24-511

11-286

<301

Alpha-amino-n-butyric Acid

Abu

<63

<56

<38

<30

<31

<19

Hydroxylysine

Hyl

<150

<57

<34

<26

<31

<12

Proline

Pro

28-2029

<119

<78

<20

<28

<26

Ornithine

Orn

<265

<70

<44

<17

<18

<25

Cystathionine

Cth

<302

<56

<26

<18

<44

<30

Cystine

Cys

12-504

11-133

<130

<56

<104

10-98

Lysine

Lys

19-1988

25-743

14-307

17-276

10-240

15-271

Methionine

Met

<41

<41

<25

<23

<20

<16

Valine

Val

11-211

11-211

<139

16-91

<75

11-61

Tyrosine

Tyr

39-685

38-479

23-254

22-245

12-208

15-115

Isoleucine

Ile

<86

<78

<62

<34

<28

<22

Leucine

Leu

<200

15-167

12-100

13-73

<62

<51

Phenylalanine

Phe

14-280

34-254

20-150

21-106

11-111

13-70

Tryptophan

Trp

14-315

14-315

10-303

10-303

15-229

18-114

Allo-isoleucine

AlloIle

<29

<10

<8

<8

<8

<7
  All results reported as nmol/mg creatinine.

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 specfic 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.

Cautions

Not all patients with homocystinuria and prolidase deficiency will be detected by this assay. See Additional Testing Requirements and Necessary Information for more information.

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.

Reporting Name

Amino Acids, QN, Random, U

Method Name

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

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

Method Description

Quantitative analysis of amino acids is performed by liquid chromatography tandem mass spectrometry (LC-MS/MS) by labeling amino acids present in plasma, urine, and cerebrospinal fluid with aTRAQ Reagent 121. Samples are dried and reconstituted with aTRAQ Reagent 113-labeled standard mix. Amino acids are separated and detected by LC-MS/MS. The concentrations of amino acids are established by comparison of their ion intensity (121-labeled amino acids) to that of their respective internal standards (113-labeled amino acids).(Unpublished Mayo method)

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
34466 Phosphoserine 28600-5
34467 Phosphoethanolamine 28604-7
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
3479 Carnosine 28597-3
34482 Anserine 28596-5
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
3481 Interpretation (AAPD) 49248-8
113130 Reviewed By 18771-6

Report Available

3 to 5 days

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.

Clinical Reference

1. Part 8: Amino Acids. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill, 2019. Accessed September 9, 2022. Available at https://ommbid.mhmedical.com/book.aspx?bookID=2709#225069340

2. Camargo SMR, Bockenhauer D, Kleta R: Aminoacidurias: Clinical and molecular aspects. Kidney Int. 2008 Apr;73(8):918-925. doi: 10.1038/sj.ki.5002790

3. Duran M: Amino acids. In: Blau N, Duran M, Gibson KM, eds. Laboratory Guide to the Methods in Biochemical Genetics. Springer-Verlag; 2008:53-89