Test Catalog

Test Id : OAUS

Organic Acids Screen, Urine Spot

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

Diagnosis of inborn errors of metabolism using dried urine specimens

Highlights

This test provides a qualitative report of abnormal levels of organic acids identified via gas chromatography-mass spectrometry.

 

Diagnostic specificity of inborn errors of metabolism via urine organic acids analysis is variable due to factors such as specimen collection when the patient is asymptomatic versus acutely ill, taking dietary supplements, or anabolic versus catabolic status of the patient.

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

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

Gas Chromatography-Mass Spectrometry (GC-MS)

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

Organic Acids Scrn, US

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

2-Ketoadipic Acid

2-Ketoglutaric Acid

3-OH Dodecanedioic Acid

3-OH Sebacic Acid

4-OH Butyric Acid

Adipic Acid

Alkaptonuria

Canavan Disease

Ethylmalonic Acid (EMA)

Fumaric Acid

GA2

Gamma-Hydroxybutyric (GHB) Acid

Gamma-OH-butyrate

Glutaric Acid

Glycerate

Homogentisic Acid

Isovaleric Acid (IVA)

Lactic Acid

MADD (Multiple Acyl-CoA Dehydrogenase Deficiency)

Malonic Acid

Methylmalonate

Mevalonic Acid

MMA (Methylmalonic Acid)

Multiple Carboxylase Deficiency

N-Acetyl Aspartic Acid

Octenedioic Acid

Pyroglutamic Acid

Pyruvic Acid

Sebacic Acid

Suberic Acid

Succinylacetone

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

Specimen Type
Describes the specimen type validated for testing

Urine

Ordering Guidance

The preferred screening test for organic acidemias is OAU / Organic Acids Screen, Random, Urine, which should be ordered unless collecting and/or sending urine is difficult or not feasible.

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

Supplies: Card-Blood Spot Collection (Filter Paper) (T493)

Collection Container:

Preferred: Blood Spot Collection Card

Acceptable: Whatman Protein Saver 903 paper, PerkinElmer 226 (formerly Ahlstrom 226) filter paper, Munktell filter paper

Specimen Volume: 1 filter paper card soaked with urine, typically requires 2 -3 mL of urine.

Collection Instructions

1. Soak a filter paper card with urine, approximately 22 cm(2) in area (typically requires 2 to 3 mL of urine; exact measurement is not important as urine volume will be normalized to creatinine). Note: Filter paper sample may be collected by dipping the card into a collection cup of urine. Avoid dilute urine if possible.

2. Let urine dry on filter paper at ambient temperature in a horizontal position for a minimum of 3 hours.

3. Do not expose specimen to heat or direct sunlight.

4. Do not stack wet specimens.

5. Keep specimen dry.

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

2 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
Urine Frozen (preferred) 28 days FILTER PAPER
Ambient 14 days FILTER PAPER
Refrigerated 14 days FILTER PAPER

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

Diagnosis of inborn errors of metabolism using dried urine specimens

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

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

Organic acids occur as physiologic intermediates in a variety of metabolic pathways. Organic acidurias are a group of disorders in which one or more of these pathways are blocked, resulting in a deficiency of normal products and an abnormal accumulation of intermediate metabolites (organic acids) in the body. These excess metabolites are excreted in the urine.

 

The incidence of individual inborn errors of organic acid metabolism varies from 1 in 10,000 to greater than 1 in 1,000,000 live births. Collectively, their incidence approximates 1 in 3000 live births. This estimate, however, does not include other inborn errors of metabolism (ie, amino acid disorders, urea cycle disorders, congenital lactic acidemias) for which diagnosis and monitoring may also require organic acid analysis. If all possible disease entities were included, the incidence of conditions where informative organic acid profiles could be detected in urine is likely to approach 1 in 1000 live births.

 

Organic acidurias typically present with either an acute life-threatening illness in early infancy or unexplained developmental delay with intercurrent episodes of metabolic decompensations in later childhood. A situation of severe and persistent metabolic acidosis of unexplained origin, elevated anion gap, and severe neurologic manifestations, such as seizures, should be considered strong diagnostic indicators of one of these diseases. The presence of ketonuria, occasionally massive, provides an important clue toward the recognition of disorders, especially in the neonatal period. Hyperammonemia, hypoglycemia, and lactic acidemia are frequent findings, especially during acute episodes of metabolic decompensations.

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.

An interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

When no significant abnormalities are detected, the organic acid analysis is reported and interpreted in qualitative terms only. 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, and recommendations for additional biochemical testing, and in vitro confirmatory studies (enzyme assay, molecular analysis).

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

The diagnostic specificity of organic acid analysis under acute and asymptomatic conditions may vary considerably.

 

Informative profiles may not always be detected in disorders where the excretion of diagnostic metabolites is a reflection of the residual activity of the defective enzyme, the dietary load of precursors, and the anabolic/catabolic status of a patient.

 

In some cases, methods of higher specificity and sensitivity such as acylcarnitine and acylglycine analysis can effectively overcome the limitations of standard organic acid analysis for the investigation of non-acutely ill patients.

Urine samples with creatinine values below 10 mg/dL may be too dilute for accurate interpretation.

 

Toluene should not be used as a preservative as it will interfere with the test.

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

1. Lehotay DC, Clarke JT: Organic acidurias and related abnormalities. Crit Rev Clin Lab Sci. 1995;32:377-429

2. Seashore MR: The Organic Acidemias: An Overview. January 2007 Accessed: February 10, 2020. Available at www.researchgate.net/publication/221964037_The_Organic_Acidemias_An_Overview

3. Chapman KA. Practical Management of Organic Acidemias. Trans Sc Rare Dis. 2019;1-12. doi: 10.3233/TRD-190039

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

Urine collected on filter paper is reconstituted in water and a volume corresponding to 0.25 mg of creatinine is acidified and then extracted with ethyl acetate. After separation and evaporation of the solvent phase, the dry residue is sialylated and analyzed by capillary gas chromatography-mass spectrometry. When indicated, oximation of 2-keto acids is performed by reaction with hydroxylamine hydrate.(Sweetman L: Organic acid analysis. In: Hommes FA, ed. Techniques in Diagnostic Human Biochemical Genetics. Wiley-Liss; 1991:143-176; Hoffman GF, Feyh P: Organic acid analysis. In: Blau N, Duran M, Blaskovics ME, Gibson KM, eds. Physician's Guide to the Laboratory Diagnosis of Metabolic Diseases. Springer; 2003:27-44; Cowan T, Pasquali M: Laboratory investigations of inborn errors of metabolism. In: Sarafoglou K, Hoffman GF, Roth KS, eds. Pediatric Endocrinology and Inborn Errors of Metabolism. 2nd ed. McGraw-Hill; 2017:1143)

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 Saturday

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 6 days

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

Filter paper urine spot: 28 days; Reconstituted urine: 2 months

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.

83919

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