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3-Aminoisobutyric acid is a product formed by the catabolism of thymine. Copyright Text is available under the Creative Commons Attribution/Share-Alike License. See for details. Source: Wikipedia, Wikipedia

Beta aminoisobutyric acid (BAIB) is a nonprotein amino acid that is an end product of pyrimidine metabolism. The R and S enantiomers (previously named D-(minus)-BAIB and L-plus-BAIB) are produced from thymine and L-valine, respectively. Under normal circumstances, urine contains predominantly R-BAIB (from thymine) because it is eliminated by filtration and tubular secretion, while plasma contains about 80% S-BAIB (from valine), which is reabsorbed in the kidneys. In patients with dihydropyrimidine dehydrogenase deficiency, thymine catabolism is decreased, which results in moderately decreased CSF concentration and markedly decreased plasma concentration of BAIB. On the other hand, urine BAIB is elevated despite decreased breakdown of thymine, which indicates that there must be cross-over in the thymine and valine degradation pathways. PMID: 14705962 Deficiency of D-beta-aminoisobutyrate:pyruvate aminotransferase (EC , an enzyme that is involved in the catabolism R-BAIB, also results in elevated urine BAIB and is associated with hyperuricemia. [OMIM: 210100] Source: Regenstrief LOINC, PMID: 14705962

Basic Part Properties

Part Display Name
Beta aminoisobutyrate
Part Type
Component (Describes the core component or analyte measured)
Created On
Construct for LOINC Short Name

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Language Variants Get Info

Tag Language Translation
zh-CN Chinese (China) Beta 氨基异丁酸
Synonyms: 3-氨基异丁酸;B-AIB;Beta-氨基异丁酸;β氨基异丁酸;β-氨基异丁酸
fr-CA French (Canada) Bêta-aminoisobutyrate
et-EE Estonian (Estonia) Beetaaminoisobutüraat
es-ES Spanish (Spain) Beta aminoisobutirato
it-IT Italian (Italy) Beta aminoisobutirrato
tr-TR Turkish (Turkey) Beta aminoizobütirat
ru-RU Russian (Russian Federation) Бета аминоизобутират
Synonyms: Бета-аминоизобутират
nl-NL Dutch (Netherlands) bèta-amino-isobutyraat
fr-BE French (Belgium) Béta-aminoisobutyrate