Organic Acids, Comprehensive, Quantitative
Performed by: Quest Diagnostics
This test is intended for the diagnosis and monitoring of inherited disorders affecting multiple metabolic pathways.
Organic acidurias are inherited disorders resulting from a deficient enzyme or transport protein. Although most are autosomal recessive disorders (= two copies of an abnormal gene must be present in order for the disease or trait to develop), several are X-linked. The more than 60 described organic acidurias affect many metabolic pathways including amino acid metabolism, lipid metabolism, purine and pyrimidine metabolism, the urea cycle, the Krebs cycle and fatty acid oxidation. These disorders are characterized by a wide variety of symptoms such as lethargy, coma, hypotonia, seizures, ataxia, vomiting, failure to thrive, developmental delay, liver disease, neutropenia, thrombocytopenia, osteomalacia and osteoporosis. Severity of presentation is highly variable as is age of onset, and patients may not present with the most characteristic features. Laboratory results commonly indicate metabolic acidosis, increased anion gap, hyperammonemia, hypoglycemia, lactic acidemia, ketosis, or abnormal lipid patterns. Treatment may be based on dietary restrictions and/or supplementation with cofactors (e.g., riboflavin or cobalamin) or conjugating agents (e.g., carnitine or sodium benzoate); however, there is no effective therapy for some of the disorders.
Elevation of one or more organic acids is diagnostic for an organic aciduria; however, elevations should be interpreted in context with clinical findings and/or additional test results. Since many organic acidurias are episodic, the diagnostic efficacy is maximized when the patient is expressing symptoms at the time of specimen collection.
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Biomarkers included in this panel:
2-Hydroxyglutaric acid is identifiable in urine by routine organic acid analysis. What is 2-hydroxyglutaric aciduria? 2-hydroxyglutaric aciduria is a rare neurometabolic disorder characterized by the significantly elevated levels of h
Learn more2-Hydroxyisocaproic acid (aka Leucic acid / α-hydroxyisocaproic acid / HICA) is a metabolite of the branched-chain amino acid leucine.
Learn more2-Hydroxyisovaleric acid (aka 2-Hydroxy-3-methylbutyric acid) is a branched-chain amino acid metabolite.
Learn more2-Methyl-3-hydroxybutyric acid, which is also known as 3-Hydroxy-2-methyl-butanoic acid (HMBA) is a normal urinary metabolite involved in the isoleucine catabolism, as well as presumably beta-oxidation of fatty acids and ketogenesis, excreted in abno
Learn more2-Methylacetoacetic acid is a metabolite that has an increased excretion in patients with acetoacetyl-CoA thiolase deficiency. Thiolases are ubiquitous and important enzymes. Several isoenzymes are known, which can occur in the cytosol, the mitochond
Learn more2-OH-3ME-Valeric (aka 3-Methyl-2-oxovaleric acid) is an abnormal metabolite that arises from the incomplete breakdown of branched-chain amino acids. Moderate increase may result from lactic acidosis, episodic ketosis, or thiamine/lipoic acid
Learn more3-Methyl-2-oxovaleric acid is an abnormal metabolite that arises from the incomplete breakdown of branched-chain amino acids. Moderate increase may result from lactic acidosis, episodic ketosis, or thiamine/lipoic acid deficiency. Significan
Learn more2-OXO-Butyric Acid is also known as Alpha-ketobutyric acid. - Alpha-ketobutyric acid results from the breakdown of threonine or methionine during glutathione production. - Specifically, cystathionine is metabolized to alpha-ketobutyric aci
Learn more2-Oxoglutaric acid is an organic acid that is important for the proper metabolism of all essential amino acids. It is formed in the Krebs cycle, the energy-producing process that occurs in most body cells.
Learn more2-Oxoisocaproic acid (also known as Ketoleucine) is an abnormal metabolite that arises from the incomplete breakdown of branched-chain amino acids. 2-Oxoisocaproic acid is both a neurotoxin and a metabotoxin.
Learn more2-Oxoisovaleric acid is an abnormal metabolite that arises from the incomplete breakdown of branched-chain amino acids (=BCAA). 2-Oxoisovaleric acid is a neurotoxin, an acidogen, and a metabotoxin.
Learn moreMetabolite of phenylalanine via phenyl pyruvate.
Learn more3-Hydroxyisovaleric Acid (3-HIA) is formed from the metabolism of the branched-chain amino acid leucine. Methylcrotonyl-CoA carboxylase catalyzes an essential step in this pathway and is biotin dependent. Reduced activity of this enzyme leads to an a
Learn more3-Hydroxypropionic acid (3-HPA) is a major urinary metabolite of propionic acid. Propionic acid is derived from dietary branched-chain amino acids, odd-chain fatty acids, and can be produced in the gut by bacterial fermentation of fiber. The biotinde
Learn more3-Hydroxyvaleric acid may be products of the condensation of propionyl-CoA with acetyl-CoA catalyzed by 3-oxoacyl-CoA thiolases. An increase amount of 3-hydroxyvaleric acid can be found in methylmalonic acidemia and propionic acidemia.
Learn moreThe marker, 3-methylglutaconic acid in high values indicates a reduced ability to metabolize the amino acid, leucine. This abnormality is found in the genetic disease, methylglutaconic aciduria and in mitochondrial disorders.
Learn more4-hydroxyphenyllactate is present in relatively higher concentrations in the cerebrospinal fluid and urine of patients with phenylketonuria (PKU) and tyrosinemia.
Learn moreA moderate urinary increase in 4-hydroxybutyric acid may be due to intake of dietary supplements containing 4-hydroxybutyric acid, also known as gamma-hydroxybutyric acid. Very high levels may indicate the genetic disorder 3-methylglutaconic aciduria
Learn more3-Hydroxyphenylacetic acid and 4-hydroxyphenylacetic acid are produced by the bacterial fermentation of amino acids, much like Indoleacetic acid (IAA).
Learn moreAKA: 4-Hydroxyphenylpyruvate, 4-HPPA 4-hydroxyphenylpyruvic acid is an intermediate in the breakdown of phenylalanine. 4-hydroxyphenylpyruvic acid is converted to homogentisate; a blockage at this step results in increased homogentisate, which
Learn morePhenylacetic acid (PAA) and phenylpropionic acid (PPA) are products of phenylalanine metabolism caused by intestinal bacteria. High levels of PAA or PPA in urine may result from the dysbiosis of intestinal flora or the decreased metabolism of phenyla
Learn morePyroglutamate (or 5-Oxoproline) is an intermediate in the glutathione metabolism and a marker of glutathione deficiency.
Learn moreAcetoacetic acid (=acetoacetate) is a ketone body and a weak Beta-keto acid produced from acetyl-CoA in the mitochondrial matrix of hepatocytes.
Learn moreElevated in mitochrondrial disorders. Aconitase metabolizes citric and aconitic acids, and is dependent on glutathione.
Learn moreDietary fatty acids are metabolized into fuel sources using beta-oxidation. Fatty acid conversion into Acetyl-CoA requires transport across the mitochondrial membrane via the carnitine shuttle. When beta-oxidation is impaired, fats are metabolized us
Learn moreCitric acid, cis-aconitic acid, and isocitric acid are the first three metabolites in the Krebs Citric Acid energy production cycle, which operates in the mitochondria of your cells.
Learn moreFumarate (together with Succinate and Malate) is used in the body’s metabolic pathway that generates cellular energy – the Citric Acid Cycle.
Learn moreGlyceric acid is an organic acid that stems from the catabolism of the amino acid serine. Severe elevations in glyceric acid are an indication of a rare inborn error of metabolism known as glyceric aciduria. One form of glyceric aciduria is the resul
Learn moreUrinary hexanoylglycine is a specific marker for the diagnosis of Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency.
Learn moreIsobutyrylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metab
Learn moreA two-carbon group from Acetyl-CoA is transferred to oxaloacetate to form citric acid. Citric acid is then converted to isocitric acid through a cis-aconitic intermediate using the enzyme aconitase. Aconitase is an iron-sulfate protein that controls
Learn moreLactic acid (Lactate) and pyruvic acid are byproducts of glycolysis. Carbohydrates, which contain glucose, are broken down through glycolysis to form pyruvate and two ATP molecules. Pyruvate can also be generated through the catabolism of various ami
Learn moreThis test measures the level of lactic acid (also known as lactate) in your blood. Lactic acid is the endproduct of the anaerobic metabolism of glucose. The blood lactic acid concentration is affected by its production in muscle cells and erythr
Learn moreFumaric acid uses the fumarase enzyme to become malic acid. Malate dehydrogenase catalyzes the conversion of malic acid into oxaloacetate. Two forms of this enzyme exist in eukaryotes. One operates within the mitochondria to contribute to the Citric
Learn moreMalonic acid is found to be associated with malonyl-CoA decarboxylase deficiency, which is an inborn error of metabolism. The name “Malonic” originates from Latin malum, meaning apple. Malonic acid is the archetypal example of a competiti
Learn moreMethylcitric is an organic acids that reflects decreased activity of the biotin-dependent enzyme propionyl-CoA carboxylase.
Learn moreOther names: Methylmalonic Acid or MMA Methylmalonic acid (MMA) is a substance produced in very small amounts and is necessary for human metabolism and energy production. In one step of metabolism, vitamin B12 promotes the conversion of methy
Learn moreN-Valerylglycine (also known as N-Pentanoylglycine) is an acyl derivative of Glycine. The presence of N-Valerylglycine (among other metabolites) in urine is used in medicine to diagnose inborn errors of metabolism (such as mitochondrial fatty acid b-
Learn morePhenylacetic acid (PAA) is produced by the bacterial metabolism of phenylalanine. Several bacterial strains are known to produce PAA, including Bacteroidetes and Clostridium species. Dietary polyphenols may also contribute to PAA elevation.
Learn morePhenyllactic acid is a metabolite of phenylalanine.
Learn morePhenylpyruvic acid is a keto-acid that is an intermediate or catabolic byproduct of phenylalanine metabolism. It has a slight honey-like odor.
Learn morePropionylglycine is a N-acylglycine obtained by formal condensation of the carboxy group of propionic acid with the amino group of glycine. It has a role as a human urinary metabolite. It is functionally related to a propionic acid. It is a conjugate
Learn moreLactic acid and pyruvic acid are byproducts of glycolysis. Carbohydrates, which contain glucose, are broken down through glycolysis to form pyruvate and two ATP molecules. Pyruvate can also be generated through the catabolism of various amino acids,
Learn moreIncreased urinary products of the omega fatty acid metabolism pathway may be due to carnitine deficiency, fasting, or increased intake of triglycerides from coconut oil, or some infant formulas.
Learn moreDietary fatty acids are metabolized into fuel sources using beta-oxidation. Fatty acid conversion into Acetyl-CoA requires transport across the mitochondrial membrane via the carnitine shuttle.80 When beta-oxidation is impaired, fats are metabolized
Learn moreSuccinate (or succinic acid) is an important metabolite that is involved in several chemical processes in the body.
Learn moreSuccinylacetone (SA) is used for the diagnosis and monitoring of patients with tyrosinemia type I (Tyr I). Succinylacetone is exclusively elevated in blood and urine of patients with tyrosinemia type I . As urinary Succinylacetone concentration is mu
Learn moreA pyrimidine (DNA building block) that is elevated in the genetic disease dihydropyrimidine dehydrogenase deficiency. In this genetic disease, the pyrimidine uracil is also elevated. - Thymine is one of the five bases used to build nucleic acids.
Learn moreTrans-Cinnamoylglycine is one component of the Acylglycines panel. Acylglycines are an important class of metabolites that are used in the diagnosis of several organic acidurias and mitochondrial fatty acid oxidation disorders.
Learn moreThe pyrimidine metabolites are markers of folate metabolism. The two markers are uracil and thymine. Folate acts as a methyl donor in converting uracil to thymine. Elevated values of uracil suggest folic acid deficiency. Folate is needed to conver
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