Test Catalog

Test Id : AACSF

Amino Acids, Quantitative, Spinal Fluid

Useful For
Suggests clinical disorders or settings where the test may be helpful

Evaluating patients with possible inborn errors of amino acid metabolism, in particular nonketotic hyperglycinemia (glycine encephalopathy) and serine biosynthesis defects, especially when used in conjunction with concomitantly collected plasma specimens

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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

 

See Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm in Special Instructions.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

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

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

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Amino Acids, QN, CSF

Aliases
Lists additional common names for a test, as an aid in searching

NKH (Nonketotic Hyperglycinemia)

Nonketotic Hyperglycinemia (NKH)

Serine Biosynthesis Defects

Glycine encephalopathy

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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

 

See Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm in Special Instructions.

Specimen Type
Describes the specimen type validated for testing

CSF

Additional Testing Requirements

This test should be ordered in conjunction with AAQP / Amino Acids, Quantitative, Plasma. The specimens for both tests (AAQP / Amino Acids, Quantitative, Plasma and AACSF / Amino Acids, Quantitative, Spinal Fluid) should be collected at the same time.

Necessary Information

1. Patient's age is required.

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

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Container/Tube: Sterile vial

Specimen Volume: 0.2 mL

Collection Instructions: Collect specimen from second collection vial.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.1 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

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

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
CSF Frozen (preferred) 14 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Evaluating patients with possible inborn errors of amino acid metabolism, in particular nonketotic hyperglycinemia (glycine encephalopathy) and serine biosynthesis defects, especially when used in conjunction with concomitantly collected plasma specimens

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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

 

See Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm in Special Instructions.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

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 and metabolism have been identified. Amino acid disorders can manifest at any age, but most become evident in infancy or early childhood. These disorders result in the accumulation or deficiency of 1 or more amino acids in biological fluids, which leads to the clinical signs and symptoms of the particular 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 mental retardation and death.

 

Cerebrospinal fluid (CSF) specimens are highly informative for a subset of these conditions, such as nonketotic hyperglycinemia and serine biosynthesis defects. CSF specimens are most informative when a plasma specimen is drawn at the same time and the ratio of the amino acid concentrations in CSF to plasma is calculated.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

CSF Amino Acid Reference Values (nmol/mL)

Age Groups

< or =31 days
(n=73)

32 days-23 months
(n=88)

2-18 years
(n=189)

> or =19 years
(n=32)

Phosphoserine (PSer)

<1

<1

<1

<1

Phosphoethanolamine (PEtN)

<15

<10

<8

<7

Taurine (Tau)

8-48

<28

<13

<20

Asparagine (Asn)

8-34

5-16

<10

5-20

Serine (Ser)

44-136

26-71

21-51

19-40

Hydroxyproline (Hyp)

<7

<3

<1

<2

Glycine (Gly)

5-115

<33

<11

<35

Glutamine (Gln)

467-1832

301-1128

326-1092

380-1348

Aspartic Acid (Asp)

<1

<1

<1

<2

Ethanolamine (EtN)

11-193

7-155

7-153

7-153

Histidine (His)

11-70

9-28

9-21

9-28

Threonine (Thr)

32-143

11-77

14-38

23-57

Citrulline (Cit)

<11

<6

<3

<9

Sarcosine (Sar)

<1

<1

<1

<1

Beta-alanine (bAla)

<26

<25

<25

<25

Alanine (Ala)

24-124

16-53

12-34

19-60

Glutamic Acid (Glu)

<12

<3

<1

<4

1-Methylhistidine (1MHis)

<3

<1

<2

<3

3-Methylhistidine (3MHis)

<4

<1

<1

<2

Argininosuccinic Acid (Asa)

<1

<2

<1

<1

Carnosine (Car)

<1

<1

<1

<1

Anserine (Ans)

<9

<9

<7

<3

Homocitrulline (Hcit)

<3

<1

<1

<1

Arginine (Arg)

5-39

11-35

11-27

11-32

Alpha-aminoadipic Acid (Aad)

<1

<1

<1

<1

Gamma-amino-n-butyric Acid (GABA)

<1

<1

<1

<1

Beta-aminoisobutyric Acid (bAib)

<1

<1

<1

<1

Alpha-amino-n-butyric Acid (Abu)

<15

<6

<5

<14

Hydroxylysine (Hyl)

<1

<1

<1

<1

Proline (Pro)

<17

<6

<2

<6

Ornithine (Orn)

<24

<12

<6

<11

Cystathionine (Cth)

<1

<2

<1

<1

Cystine (Cys)

<2

<2

<1

<1

Lysine (Lys)

11-63

9-33

10-25

13-42

Methionine (Met)

<43

<9

<6

<10

Valine (Val)

14-61

9-28

8-20

11-40

Tyrosine (Tyr)

8-83

5-24

<17

5-17

Isoleucine (Ile)

<27

<13

<8

<17

Leucine (Leu)

12-41

6-21

7-16

7-29

Phenylalanine (Phe)

7-40

5-18

<12

7-21

Tryptophan (Trp)

<12

<6

<4

<4

Allo-isoleucine (AlloIle)

<3

<2

<2

<2

 

Interpretation
Provides information to assist in interpretation of the test results

When no significant abnormalities are detected, a simple descriptive interpretation is provided. When abnormal results are detected, a detailed interpretation is provided. This interpretation includes an overview of the results and their significance, a correlation to available clinical information, elements of differential diagnosis, and 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 the telephone number to reach one of the laboratory directors in case the referring physician has additional questions.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Proper specimen collection and handling are crucial to achieve reliable results. Blood contamination can interfere with test results.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Rinaldo P, Hahn S, Matern D: Inborn errors of amino acid, organic acid, and fatty acid metabolism. In Tietz Textbook of Clinical Chemistry and Molecular Diagnosis. Fourth edition. Edited by CA Burtis, ER Ashwood, DE Bruns. St. Louis, WB Saunders Company, 2005, pp 2207-2247

2. Van Hove J, Coughlin C II, Scharer G: Glycine Encephalopathy. In GeneReviews. 2002 Nov 14. Edited by MP Adam, HH  Ardinger, RA Pagon, et al. Retrieved 2019 May 10. Available at https://www.ncbi.nlm.nih.gov/books/NBK1357/  

3. El-Hattab AW: Serine biosynthesis and transport defects. Mol Genet Metab 2016;118:153-159

4. Duran M: Amino acids. In Laboratory Guide to the Methods in Biochemical Genetics. Edited by N Blau, M Duran, KM Gibson. Springer-Verlag, Berlin Heidelberg, 2008, pp 53-89

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

Quantitative analysis of the amino acids is performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) by labeling amino acids present in cerebrospinal fluid (CSF) 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).(Lacey JM, Casetta B, Daniels SB, et al: Quantitation in plasma, urine and CSF by iTRAQ reagent amino acid analysis kit and MS-MS. J Am Soc Mass Spectrom [2008] 19[5] S97)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

3 to 5 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

2 weeks

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

82139

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports