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Test ID: AACSF
Amino Acids, Quantitative, Spinal Fluid

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

Conditional

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 hyperglycemia and serine biosynthesis defects, especially when used in conjunction with concomitantly drawn plasma specimens

Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request

This test must be ordered in conjunction with AAQP/9265 Amino Acids, Quantitative, Plasma. The specimens for both tests AAQP/9265 Amino Acids, Quantitative, Plasma and AACSF/81934 Amino Acids, Quantitative, Spinal Fluid) must be collected at the same time.

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

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

                                                                 

Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name

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

Specimen Type Describes the specimen type needed for testing

CSF

Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

Container/Tube: Sterile vial

Specimen Volume: 0.2 mL

Collection Instructions: Collect specimen from second collection vial.

Additional Information: 

1. Patient's age is required.

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

Forms: If not ordering electronically, submit a Biochemical Genetics Request Form (Supply T439) with the specimen.

Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.

0.1 mL

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

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

NA

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
CSFFrozen14 days

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

Many genetic errors affecting amino acid metabolism have been identified. Defects of either transport or catalytic activity of enzymes involved in this pathway result in accumulation or excessive loss of 1 or more amino acids in biological fluids. Inborn errors of amino acid metabolism can manifest themselves at anytime in a person’s life, but most become evident in infancy and early childhood. Affected patients may have failure to thrive, neurological symptoms, digestive problems, locomotor retardation, and a wide spectrum of laboratory findings. If not diagnosed promptly and treated properly, these disorders can result in poor growth, 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

Homocystine (Hcy)

<1

<1

<1

<1

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 given. 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 at Mayo Clinic or elsewhere, 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 Provides recommendations for further in-depth reading of a clinical nature

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

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 (API 3200). 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). Chromatography is performed using a C18 (150x4.6mm) column and total analysis time is 18 minutes.(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 Spec [200] 19[5] S97)

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

Monday through Friday; 8:00 a.m.

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

3 days (not reported on Saturday or Sunday)

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

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 The location of the laboratory that performs the test

Rochester

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's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) 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 U.S. 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 Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

82139

LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.

Result IDReporting NameLOINC Code
34564PhosphoserineIn Process
34565Phosphoethanolamine26597-5
81934Taurine26614-8
30109Asparagine26603-1
30108Serine22644-9
34566HydroxyprolineIn Process
30115Glycine22650-6
30111Glutamine22641-5
34567Aspartic Acid22655-5
34568EthanolamineIn Process
30128Histidine9453-2
30107Threonine22643-1
30117Citrulline22654-8
34569Sarcosine26598-3
34570Beta-alanine26589-2
30116Alanine22657-1
30110Glutamic Acid22652-2
345711-Methylhistidine26584-3
345723-MethylhistidineIn Process
34573Argininosuccinic AcidIn Process
34574CarnosineIn Process
34575AnserineIn Process
34576HomocitrullineIn Process
30129Arginine22656-3
34577Alpha-aminoadipic AcidIn Process
34578Gamma-amino-n-butyric AcidIn Process
34579Beta-aminoisobutyric AcidIn Process
30118Alpha-amino-n-butyric Acid26586-8
34580HydroxylysineIn Process
30112Proline22645-6
30126Ornithine22647-2
34581CystathionineIn Process
30120Cystine22653-0
30127Lysine22651-4
30121Methionine22648-0
30119Valine22649-8
30124Tyrosine22642-3
30122Isoleucine22659-7
30123Leucine9412-8
30125Phenylalanine22646-4
34582TryptophanIn Process
34583Allo-isoleucineIn Process
50435Interpretation59462-2