Normal Function
The AGXT gene provides instructions for making an enzyme called alanine-glyoxylate aminotransferase. This enzyme is found in liver cells, specifically within cell structures called peroxisomes. These structures are important for several cellular activities, such as ridding the cell of toxic substances and helping to break down certain fats. In the peroxisome, alanine-glyoxylate aminotransferase converts a compound called glyoxylate to the protein building block (amino acid) glycine.
Health Conditions Related to Genetic Changes
Primary hyperoxaluria
More than 175 mutations in the AGXT gene have been found to cause primary hyperoxaluria type 1. This condition is caused by the overproduction of a substance called oxalate. Excess amounts of this substance lead to kidney and bladder stones, which can begin anytime from childhood to early adulthood with kidney disease developing at any age. Deposition of oxalate in multiple other tissues throughout the body (systemic oxalosis) can cause additional health problems.
Most of the AGXT gene mutations decrease or eliminate alanine-glyoxylate aminotransferase activity, which impairs the conversion of glyoxylate to glycine. Other mutations cause the enzyme to be misplaced in cells, transporting it to structures called mitochondria instead of to peroxisomes. While the enzyme in the mitochondria retains activity, it cannot access glyoxylate, which is in peroxisomes. All AGXT gene mutations result in the accumulation of glyoxylate, which is converted to oxalate instead of glycine. The oxalate is filtered through the kidneys and is either excreted in urine as a waste product or combines with calcium to form calcium oxalate, a hard compound that is the main component of kidney and bladder stones. Increased oxalate levels in the blood can lead to systemic oxalosis, particularly affecting bones and the walls of blood vessels in people with primary hyperoxaluria type 1.
More About This Health ConditionOther Names for This Gene
- AGT
- AGT1
- AGXT1
- alanine glyoxylate aminotransferase
- alanine-glyoxylate aminotransferase
- alanine-glyoxylate aminotransferase (oxalosis I; hyperoxaluria I; glycolicaciduria; serine-pyruvate aminotransferase)
- alanine-glyoxylate transaminase
- L-alanine: glyoxylate aminotransferase 1
- pyruvate (glyoxylate) aminotransferase
- serine-pyruvate aminotransferase
- serine:pyruvate aminotransferase
- SPAT
- SPT
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
References
- Cochat P, Rumsby G. Primary hyperoxaluria. N Engl J Med. 2013 Aug 15;369(7):649-58. doi: 10.1056/NEJMra1301564. No abstract available. Erratum In: N Engl J Med. 2013 Nov 28;369(22):2168. Citation on PubMed
- Hopp K, Cogal AG, Bergstralh EJ, Seide BM, Olson JB, Meek AM, Lieske JC, Milliner DS, Harris PC; Rare Kidney Stone Consortium. Phenotype-Genotype Correlations and Estimated Carrier Frequencies of Primary Hyperoxaluria. J Am Soc Nephrol. 2015 Oct;26(10):2559-70. doi: 10.1681/ASN.2014070698. Epub 2015 Feb 2. Citation on PubMed or Free article on PubMed Central
- Milliner DS, Harris PC, Sas DJ, Cogal AG, Lieske JC. Primary Hyperoxaluria Type 1. 2002 Jun 19 [updated 2024 Aug 15]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from http://www.ncbi.nlm.nih.gov/books/NBK1283/ Citation on PubMed
- Williams EL, Acquaviva C, Amoroso A, Chevalier F, Coulter-Mackie M, Monico CG, Giachino D, Owen T, Robbiano A, Salido E, Waterham H, Rumsby G. Primary hyperoxaluria type 1: update and additional mutation analysis of the AGXT gene. Hum Mutat. 2009 Jun;30(6):910-7. doi: 10.1002/humu.21021. Citation on PubMed
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