Evaluating patients with possible inborn errors of metabolism using plasma specimens
May aid in evaluation of endocrine disorders, liver diseases, muscle diseases, neoplastic diseases, neurological disorders, nutritional disturbances, kidney failure, and burns
Testing 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, homocitrulline, alpha-aminoadipic acid, gamma-amino-n-butyric acid, beta-aminoisobutyric acid, hydroxylysine, cystathionine, and tryptophan.
For more information see Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm.
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Portions of this test are covered by patents held by Quest Diagnostics
Maple Syrup Urine Disease (MSUD)
MSUD (Maple Syrup Urine Disease)
Isovaleric Acidemia
Methylmalonic Acidemia (MMA)
Mitochondrial Energy Metabolism (Primary Lactic Acidemias)
Nonketotic Hyperglycinemia (NKH)
Phenylketonuria (PKU)
Propionic Acidemia
Tyrosinemia, Type I
Urea Cycle Disorders
Arginase Deficiency
Argininemia
Argininosuccinic Acid
Argininosuccinic Acid Lyase Deficiency
Argininosuccinic Aciduria
Carbamoyl Phosphate Synthetase (CPS) Deficiency
Citrullinemia
N-acetyl Glutamate Synthase (NAGS) Deficiency
NAGS (N-acetyl Glutamate Synthetase)
Ornithine Transcarbamylase (OTC) Deficiency
OTC (Ornithine Transcarbamylase)
UCD (Urea Cycle Disorder)
Urea Cycle Disorder (AAUCD)
Maple syrup disease
Hyperphenylalaninemia
Tyrosinemia, type II
CPS (Carbamoyl Phosphate Synthetase)
Testing 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, homocitrulline, alpha-aminoadipic acid, gamma-amino-n-butyric acid, beta-aminoisobutyric acid, hydroxylysine, cystathionine, and tryptophan.
For more information see Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm.
Plasma
Not all patients with homocystinuria/homocystinemia will be detected by this assay. If there is a concern for homocystinemia, order HCYSP / Homocysteine, Total, Plasma in conjunction with this amino acids profile.
Send plasma frozen.
1. Patient's age is required.
2. Include family history, clinical condition (asymptomatic or acute episode), diet, and drug therapy information.
Patient Preparation: Fasting (overnight preferred, 4 hours minimum). Infants should be drawn just before next feeding (2-3 hours without total parenteral nutrition, if possible).
Collection Container/Tube:
Preferred: Green top (sodium heparin)
Acceptable: Lavender top (EDTA), plasma gel tube, green top (lithium heparin)
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions:
1. Collect specimen and place on wet ice. Note: Thrombin-activated tubes should not be used for collection.
2. Centrifuge immediately or within 4 hours of collection if the specimen is kept at refrigerated temperature.
3. Being careful to ensure that no buffy coat is transferred, aliquot plasma into a plastic vial and freeze.
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
0.3 mL
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma | Frozen | 14 days |
Evaluating patients with possible inborn errors of metabolism using plasma specimens
May aid in evaluation of endocrine disorders, liver diseases, muscle diseases, neoplastic diseases, neurological disorders, nutritional disturbances, kidney failure, and burns
Testing 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, homocitrulline, alpha-aminoadipic acid, gamma-amino-n-butyric acid, beta-aminoisobutyric acid, hydroxylysine, cystathionine, and tryptophan.
For more information see Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm.
Amino acids are the basic structural units that comprise proteins and are found throughout the body. Many inborn errors of amino acid metabolism, such as phenylketonuria and tyrosinemia, 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 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.
Treatment for amino acid disorders includes very specific dietary modifications. Nonessential amino acids are synthesized by the body, while essential amino acids are not and must be obtained through an individual's diet. Therapeutic diets are coordinated and closely monitored by a dietician or physician. They are structured to provide the necessary balance of amino acids with particular attention to essential amino acids and those that accumulate in a particular disorder. Patients must pay close attention to the protein content in their diet and generally need to supplement with medical formulas and foods. Dietary compliance is monitored by periodic analysis of plasma amino acids.
In addition, plasma 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.
Amino acids | Age groups | ||
<24 months | 2-17 years | > or =18 years | |
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) | 316-1,020 | 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 |
b-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 |
a-Aminoadipic Acid (Aad) | <4 | <3 | <3 |
g-Amino-n-butyric Acid (GABA) | <4 | <3 | <2 |
b-Aminoisobutyric Acid (bAib) | <9 | <5 | <5 |
a-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 |
Isoleucine (IIe) | 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 |
Alloisoleucine (Allolle) | <2 | <3 | <5 |
All results reported in nmol/mL
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 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.
Reference values are for fasting patients.
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 Sep 9, 2022 Available at https://ommbid.mhmedical.com/book.aspx?bookID=2709#225069340
2. 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
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 spinal 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-MSMS. 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)
Monday through Friday
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.
82139
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
AAQP | Amino Acids, QN, P | 35083-5 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
3512 | Taurine | 20657-3 |
3517 | Asparagine | 20638-3 |
3516 | Serine | 20656-5 |
3522 | Glycine | 20644-1 |
3518 | Glutamine | 20643-3 |
3535 | Histidine | 20645-8 |
3515 | Threonine | 20658-1 |
3521 | Citrulline | 20640-9 |
3532 | Beta-Alanine | 26604-9 |
3523 | Alanine | 20636-7 |
3520 | Glutamic Acid | 20642-5 |
32341 | Argininosuccinic Acid | 32227-1 |
3536 | Arginine | 20637-5 |
3524 | Alpha-amino-n-butyric Acid | 20634-2 |
3519 | Proline | 20655-7 |
3533 | Ornithine | 20652-4 |
3526 | Cystine | 22672-0 |
3534 | Lysine | 20650-8 |
3527 | Methionine | 20651-6 |
3525 | Valine | 20661-5 |
3530 | Tyrosine | 20660-7 |
3528 | Isoleucine | 20648-2 |
3529 | Leucine | 20649-0 |
3531 | Phenylalanine | 14875-9 |
3570 | Interpretation (AAQP) | 49247-0 |
32347 | Allo-isoleucine | 22670-4 |
34449 | Phosphoserine | 20654-0 |
34450 | Alpha-aminoadipic Acid | 26600-7 |
34451 | Cystathionine | 26607-2 |
34452 | Beta-aminoisobutyric Acid | 26605-6 |
34453 | 1-Methylhistidine | 20633-4 |
34454 | 3-Methylhistidine | 20635-9 |
34455 | Carnosine | 26606-4 |
34456 | Homocitrulline | 55876-7 |
34457 | Phosphoethanolamine | 26612-2 |
34458 | Hydroxyproline | 20647-4 |
34459 | Aspartic Acid | 20639-1 |
34460 | Ethanolamine | 26608-0 |
34461 | Sarcosine | 26613-0 |
34462 | Anserine | 26599-1 |
34463 | Gamma-amino-n-butyric Acid | 26609-8 |
34464 | Hydroxylysine | 26610-6 |
34465 | Tryptophan | 20659-9 |