Sign in →

Test ID: OAUS Organic Acids Screen, Urine Spot


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


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.


Useful For

Diagnosis of inborn errors of metabolism using dried urine specimens

Method Name

Gas Chromatography-Mass Spectrometry (GC-MS)

Reporting Name

Organic Acids Scrn, US

Specimen Type

Urine

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen (preferred) 28 days FILTER PAPER
  Ambient  14 days FILTER PAPER
  Refrigerated  14 days FILTER PAPER

Clinical Information

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

An interpretive report will be provided.

Interpretation

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).

Clinical Reference

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

Day(s) Performed

Monday through Saturday

Report Available

3 to 6 days

Test Classification

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

83919

LOINC Code Information

Test ID Test Order Name Order LOINC Value
OAUS Organic Acids Scrn, US 49287-6

 

Result ID Test Result Name Result LOINC Value
610707 Organic Acids Scrn, US 49287-6
Mayo Clinic Laboratories | Genetics and Pharmacogenomics Catalog Additional Information:

mml-biochemical