Organic Acids (Complete), Urine (Sendout)

General Information

Lab Name

Organic Acids (Complete), URN

Lab Code

RUORGC

Epic Name

Organic Acids (Complete), Urine

External Test Id

LAB418

Description

Clinical Utility: Urine organic acids can be used for diagnosis and monitoring in patients with disorders of amino acid, organic acid, and fatty acid metabolism. This test is often used in conjunction with plasma acylcarnitines for follow up of presumptive positives in the newborn screening program. The following conditions typically show abnormalities in the urine organic acid profile: Alcaptonuria (homogentisic acid), Biotinidase deficiency, Canavan disease (N-acetylaspartic acid), Fatty Acid Oxidation Defects (MCAD, VLCAD, LCHAD), Fructose-1,6-diphosphatase deficiency (glycerol), Fumarase deficiency, Glutaric aciduria type 1 & 2, Glycerol kinase deficiency (glycerol), Hawkinsinuria (4-hydroxycyclohexylacetic acid), HMG CoA lyase deficiency, Holocarboxylase synthase deficiency, Hyperoxaluria type 1 & 2, Isovaleric aciduria, Ketosis, Ketothiolase deficiency, Malonyl-CoA dehydrogenase deficiency, Maple Syrup Urine Disease, Methylmalonic aciduria, 3-methylcrotonyl CoA carboxylase deficiency, Mevalonic aciduria (mevalonolactone), Multiple acyl-CoA dehydrogenase deficiency (glutaric aciduria type 2), Multiple carboxylase deficiency, Ornithine transcarbamylase deficiency (orotic acid), Phenylketonuria, Propionic aciduria, Succinic semialdehyde dehydrogenase deficiency (4-hydroxybutyric acid), Tyrosinemia type 1 (succinylacetone), and Tyrosinemia type 2.

Test Description: Organic acids are extracted from urine at acid pH with ethyl acetate and ether, and derivatized with hydroxylamine and BSTFA. Separation is accomplished by gas chromatography and identification by mass spectrometry using a library of 200 compounds. Semi-quantitative results are reported for 13 organic acids. The following organic acids are always reported: 2-Ketoglutaric, 3-Methylglutaconic, 3-Methylglutaric, 3-OH-Butyric Acid, Acetoacetic, Adipic, Ethylmalonic, Fumaric, Glutaric, Lactic, Pyruvic, Sebacic, and Suberic acids. Other clinically relevant organic acids will be reported, if present.

Collection Timing: Samples are best collected while patient is ill. Testing asymptomatic patients may yield false negative results. Succinylacetone is included in this test, however, please note if tyrosinemia type 1 is suspected. Quantitative succinylacetone is suggested for follow-up monitoring of confirmed patients.

Ordering Requirements: Include relevant clinical information (drug therapy, family history, etc.) in the Epic order comment to ensure proper interpretation.

References

• Seattle Children's Hospital Laboratory Test: Organic Acids, Urine

Forms & Requisitions

• Seattle Children's Hospital Laboratory Biochemical Genetics Requisition (DLMP use only)

Synonyms

2-ketoglutaric acid, 2-OH-glutaric acid, 3-MCC, 3-Methylglutaconic acid, 3-Methylglutaric acid, 3-OH-3-Methylglutaric acid, 3-OH-Butyric acid, 3-OH-Isovaleric acid, 3-OH-Phenylacetic acid, 3-OH-Sebacic acid, 4-OH-Mandelic acid, 5-Oxoproline acid, Acetoacetic acid, Aconitic acid, Adipic acid, Alpha-ketoglutaric acid, Biotinidase, Ethylmalonic acid, Fumarase, Fumaric acid, Glutaric acid, Hawkinsinuria, Hexenedioic acid, Hippuric acid, Holocarboxylase, IVA, Ketosis, LAB418, Lactic acid, P-OH-Phenylacetic acid, P-OH-Phenyllactic acid, P-OH-Phenylpyruvic acid, Pyroglutamic acid, Pyruvic acid, Sebacic acid, Suberic acid, Succinic acid, Tylenol toxicity, Tyrosinemia

Components

Code	Name
RULAC	Lactic Acid, URN
RUPYR	Pyruvic Acid, URN
RU3BUT	3_OH Butyric Acid, URN
RUACE	Acetoacetic Acid, URN
RUETHM	Ethylmalonic Acid, URN
RUFUM	Fumaric Acid, URN
RUGLUT	Glutaric Acid, URN
RU3MGC	3_Methylglutaconic Acid, URN
RU3MG	3_Methylglutaric Acid, URN
RUADIP	Adipic Acid, URN
RU2KET	2_Ketoglutaric Acid, URN
RUSUB	Suberic Acid, URN
RUSEB	Sebacic Acid, URN
RUWOTR	Organic acids, other
RUXORN	Organic Acid Interp., URN
RUZORC	Organic Acid Comment, URN