Test ID: AAMSD
Amino Acids, Maple Syrup Urine Disease Panel, Plasma
NY State Approved 
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Follow-up of patients with maple syrup urine disease
Monitoring of dietary compliance for patients with maple syrup urine disease
Method Name A short description of the method used to perform the test
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Isoleucine
Leucine
Maple Syrup Disease (MSD)
Maple Syrup Urine Disease (MSUD)
MSD (Maple Syrup Disease)
MSUD (Maple Syrup Urine Disease)
Valine
Specimen Type Describes the specimen type needed for testing
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.
Collection Container/Tube:
Preferred: Green top (sodium heparin)
Acceptable: EDTA, plasma gel, or lithium heparin
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions:
1. Fasting (12 hours). Infants should be drawn just before next feeding.
2. Spin down promptly.
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.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross OK |
| Lipemia | Mild OK; Gross OK |
| Icterus | Mild OK; Gross OK |
| Other | Thrombin-activated tube |
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 Type | Temperature | Time |
|---|---|---|
| Plasma | Frozen | 14 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Maple syrup urine disease (MSUD) is an autosomal recessive deficiency of the branched-chain ketoacid dehydrogenase (BCKDH) complex. The BCKDH complex is involved in the metabolism of the branched-chain amino acids (BCAA): isoleucine (Ile), leucine (Leu), and valine (Val). Classic MSUD presents in the neonate with feeding intolerance, failure to thrive, vomiting, lethargy, and maple syrup odor to urine and cerumen. If untreated, it progresses to irreversible mental retardation, hyperactivity, failure to thrive, seizures, coma, cerebral edema, and possibly death.
MSUD is a panethnic condition, but is most prevalent in the Old Order Mennonite community in Lancaster, Pennsylvania. The incidence of MSUD is approximately 1:200,000 live births in the general population and 1:760 live births among the Old Order Mennonites.
Treatment of MSUD aims to normalize the concentration of BCAA by dietary restriction of these amino acids. Because BCAA belong to the essential amino acids, the dietary treatment requires frequent adjustment, which is accomplished by regular determination of BCAA and allo-isoleucine concentrations.
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.
ISOLEUCINE
< or =23 months: 31-105 nmol/mL
2-17 years: 30-111 nmol/mL
> or =18 years: 36-107 nmol/mL
LEUCINE
< or =23 months: 48-175 nmol/mL
2-17 years: 51-196 nmol/mL
> or =18 years: 68-183 nmol/mL
VALINE
< or =23 months: 83-300 nmol/mL
2-17 years: 106-320 nmol/mL
> or =18 years: 136-309 nmol/mL
ALLO-ISOLEUCINE
< or =23 months: <2 nmol/mL
2-17 years: <3 nmol/mL
> or =18 years: <5 nmol/mL
Interpretation Provides information to assist in interpretation of the test results
The quantitative results of isoleucine, leucine, valine, and allo-isoleucine with age-dependent reference values are reported without added interpretation. When applicable, reports of abnormal results may contain an interpretation based on available clinical interpretation.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Reference values are for fasting patients.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Amino acids. In The Metabolic and Molecular Bases of Inherited Disease. 8th edition. Edited by CR Scriver, AL Beaudet, WS Sly, et al. New York, McGraw-Hill, Inc 2001, pp 1667-2105
Method Description Describes how the test is performed and provides a method-specific reference
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-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. (Unpublished Mayo method)
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 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.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
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.
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.
82136
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 ID | Reporting Name | LOINC Code |
|---|---|---|
| 32446 | Valine | 20661-5 |
| 32447 | Isoleucine | 20648-2 |
| 32448 | Leucine | 20649-0 |
| 32449 | Allo-isoleucine | 22670-4 |
| 32450 | Interpretation (AAMSD) | 59462-2 |
External
link
PDF
document
Excel
document
Word
document