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Test ID: OAU Organic Acids Screen, Urine

Reporting Name

Organic Acids Scrn, U

Useful For

Diagnosis of inborn errors of metabolism

Testing Algorithm

The following algorithms are available in Special Instructions:

-Newborn Screening Follow-up for Elevations of C8, C6, and C10 Acylcarnitines (also applies to any plasma or serum C8, C6, and C10 acylcarnitine elevations)

-Newborn Screening Follow-up for Isolated C4 Acylcarnitine Elevations (also applies to any plasma or serum C4 acylcarnitine elevation)

-Newborn Screening Follow-up for Isolated C5 Acylcarnitine Elevations (also applies to any plasma or serum C5 acylcarnitine elevation)

Specimen Type

Urine


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: Urine Tubes, 10 mL (T068)

Specimen Volume: 10 mL

Pediatric: If insufficient collection volume, submit as much specimen as possible in a single container; the laboratory will determine if volume is sufficient for testing.

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.


Specimen Minimum Volume

4 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Frozen (preferred) 416 days
  Refrigerated  14 days

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Saturday; 7 a.m.

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 U.S. Food and Drug Administration.

CPT Code Information

83919

LOINC Code Information

Test ID Test Order Name Order LOINC Value
OAU Organic Acids Scrn, U In Process

 

Result ID Test Result Name Result LOINC Value
80619 Organic Acids Scrn, U 2676-5

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 >1 in 1,000,000 live births. Collectively, their incidence approximates 1 in 3,000 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. All possible disease entities included, the incidence of conditions where informative organic acid profiles could be detected in urine is likely to approach 1 in 1,000 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.

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. Reviewed April 8, 2015. Available at www.researchgate.net/publication/221964037_The_Organic_Acidemias_An_Overview

Analytic Time

3 days (not reported on Sunday)

Method Name

Gas Chromatography-Mass Spectrometry (GC-MS)

Mayo Medical Laboratories | Genetics and Pharmacogenomics Catalog Additional Information:

mml-biochemical