Amino Acids, Quantitative
Label Mnemonic: AAQTP
Epic Lab Code: LAB2578
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
Plasma
Specimen Instructions:
Patient's age is required on request form for processing. Include family history, clinical condition (asymptomatic or acute episode), diet, and drug therapy information.
Collection Medium:
Green top tube 4 mL (Na Heparin)
Minimum:
Preferred Minimum: 4 mL heparinized plasma in a green-top (heparin) tube from a fasting patient (4 hours or more in infants).
Absolute Minimum: 0.5 mL heparinized plasma
Rejection Criteria:
Thrombin-activated tube is not acceptable.
Testing Schedule:
Monday through Friday
Turn Around Time:
3 days upon receipt at reference laboratory (not reported on Saturday or Sunday)
Reference Range:
                                                    Age Groups
 Plasma Amino Acid Reference       < 24 m       2y - 17 y    > or =18 y
      Values (nmol/mL)             (n=191)       (n=441)        (n=148)
-----------------------------------------------------------------------
Phosphoserine            PSer       < 109          < 95           < 18
Phosphoethanolamine      PEtN       < 6            < 5            < 12
Taurine                  Tau     37 - 177       38 - 153       42 - 156
Asparagine               Asn     25 - 91        29 - 87        37 - 92
Serine                   Ser     69 - 271       71 - 208       63 - 187
Hydroxyproline           Hyp      8 - 61         7 - 35         4 - 29
Glycine                  Gly    111 - 426      149 - 417      126 - 490
Glutamine                Gln    316 - 1020     329 - 976      371 - 957
Aspartic Acid            Asp      2 - 20           < 11           < 7
Ethanolamine             EtN        < 70           < 64           < 67
Histidine                His     10 - 116       12 - 132       39 - 123
Threonine                Thr     47 - 237       58 - 195       85 - 231
Citrulline               Cit      9 - 38        11 - 45        17 - 46
Sarcosine                Sar        < 5            < 5            < 5
Beta-Alanine             bAla       < 28           < 27           < 29
Alanine                  Ala    139 - 474      144 - 557      200 - 579
Glutamic Acid            Glu     31 - 202       22 - 131       13 - 113
1-Methylhistidine       1MHis       < 11           < 20           < 28
3-Methylhistidine       3MHis       < 1            < 1          2 - 9
Argininosuccinic Acid    Asa        < 2            < 2            < 2
Carnosine                Car        < 13           < 1            < 1
Anserine                 Ans        < 1            < 1            < 1
Homocitruline            Hcit       < 5            < 2            < 2
Arginine                 Arg     29 - 134       31 - 132       32 - 120
Alpha-Aminoadipic Acid   Aad       < 4             < 3            < 3
Gamma-Amino-n-
  butyric Acid           GABA      < 4             < 3            < 2
Beta-Aminoisobutyric
  Acid                   bAib      < 9             < 5            < 5
Alpha-Amino-n-
  Butyric Acid           Abu     7 - 28          7 - 31         9 - 37
Hydroxylysine            Hyl       < 4             < 3            < 2
Proline                  Pro    85 - 303        80 - 357       97 - 368
Ornithine                Orn    20 - 130        22 - 97        38 - 130
Cystathionine            Cth       < 2             < 2            < 5
Cystine                  Cys     2 - 32          2 - 36         3 - 95
Lysine                   Lys    49 - 204        59 - 240      103 - 255
Methionine               Met    11 - 35         11 - 37         4 - 44
Valine                   Val    83 - 300       106 - 320      136 - 309
Tyrosine                 Tyr    26 - 115        31 - 106       31 - 90
Homocystine              Hcy       NA              NA             < 5
Isoleucine               Ile    31 - 105        30 - 111       36 - 107
Leucine                  Leu    48 - 175        51 - 196       68 - 183
Phenylalanine            Phe    28 - 80         30 - 95        35 - 80
Tryptophan               Trp    17 - 75         23 - 80        29 - 77
Allo-isoleucine         AlloIle    < 2             < 3            < 5

Reference values are for fasting patients.
Interpretive Data:
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 at the reference laboratory or elsewhere, and a phone number to reach one of the laboratory directors in case the referring physician has additional questions.
Comments:
Useful for:
Evaluating patients with possible inborn errors of metabolism.

May aid in evaluation of endocrine disorders, liver diseases, muscle diseases, neoplastic diseases, neurological disorders, nutritional disturbances, renal failure, and burns.
Test Limitations:
Biochemical test results depend in part on the clinical and dietary status at the time of specimen collection. A normal or non-diagnostic test result does not rule out the possibility of an underlying metabolic disorder, including that for which the test was requested.
Methodology:
Quantitative Analysis by Liquid Chromatography-Tandem Mass Spectometry (LC-MS/MS)

Includes quantitation of the following amino acids: taurine, threonine, serine, asparagine, glutamic acid, glutamine, proline, alanine, citrulline, alpha-amino-n-butyric acid, valine, cystine, methionine, isoleucine, leucine, tyrosine, phenylalanine, beta-alanine, ornithine, lysine, histidine, argininosuccinic acid, allo-isoleucine, arginine, phosphoserine, phosphoethanolamine, hydroxyproline, glycine, aspartic acid, ethanolamine, sarcosine, 1-methylhistidine, 3-methylhistidine, carnosine, anserine, homocitruline, alpha-aminoadipic acid, gamma- amino- n-butyric acid, beta-aminoisobutyric acid, hydroxylysine, cystathionine, and tryptophan.
CPT Code:
82139
 
See Additional Information:
Fasting Specimen Requirements