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ACOX1 gene

acyl-CoA oxidase 1

Normal Function

The ACOX1 gene provides instructions for making an enzyme called peroxisomal straight-chain acyl-CoA oxidase. This enzyme is found in sac-like cell structures (organelles) called peroxisomes, which contain a variety of enzymes that break down many different substances. The peroxisomal straight-chain acyl-CoA oxidase enzyme plays a role in the breakdown of certain fat molecules called very long-chain fatty acids (VLCFAs). Specifically, it is involved in the first step of a process called the peroxisomal fatty acid beta-oxidation pathway. This process shortens the VLCFA molecules by two carbon atoms at a time until the VLCFAs are converted to a molecule called acetyl-CoA, which is transported out of the peroxisomes for reuse by the cell.

Health Conditions Related to Genetic Changes

Peroxisomal acyl-CoA oxidase deficiency

More than 20 ACOX1 gene mutations have been identified in people with peroxisomal acyl-CoA oxidase deficiency. These mutations prevent the peroxisomal straight-chain acyl-CoA oxidase enzyme from breaking down VLCFAs efficiently. As a result, these fatty acids accumulate in the body. It is unclear exactly how VLCFA accumulation leads to the specific features of peroxisomal acyl-CoA oxidase deficiency. However, researchers suggest that the abnormal fatty acid accumulation triggers inflammation in the nervous system that leads to the breakdown of myelin, which is the covering that protects nerves and promotes the efficient transmission of nerve impulses. Destruction of myelin leads to a loss of myelin-containing tissue (white matter) in the brain and spinal cord; loss of white matter is described as leukodystrophy. Leukodystrophy is likely involved in the development of the neurological abnormalities that occur in peroxisomal acyl-CoA oxidase deficiency.

More About This Health Condition

Other Names for This Gene

  • ACOX
  • acyl-CoA oxidase 1, palmitoyl
  • acyl-CoA oxidase, straight-chain
  • acyl-Coenzyme A oxidase 1, palmitoyl
  • AOX
  • palmitoyl-CoA oxidase
  • peroxisomal acyl-coenzyme A oxidase 1
  • peroxisomal fatty acyl-CoA oxidase
  • SCOX
  • straight-chain acyl-CoA oxidase

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Carrozzo R, Bellini C, Lucioli S, Deodato F, Cassandrini D, Cassanello M, Caruso U, Rizzo C, Rizza T, Napolitano ML, Wanders RJ, Jakobs C, Bruno C, Santorelli FM, Dionisi-Vici C, Bonioli E. Peroxisomal acyl-CoA-oxidase deficiency: two new cases. Am J Med Genet A. 2008 Jul 1;146A(13):1676-81. doi: 10.1002/ajmg.a.32298. Citation on PubMed
  • Clayton PT. Clinical consequences of defects in peroxisomal beta-oxidation. Biochem Soc Trans. 2001 May;29(Pt 2):298-305. doi: 10.1042/0300-5127:0290298. Citation on PubMed
  • El Hajj HI, Vluggens A, Andreoletti P, Ragot K, Mandard S, Kersten S, Waterham HR, Lizard G, Wanders RJ, Reddy JK, Cherkaoui-Malki M. The inflammatory response in acyl-CoA oxidase 1 deficiency (pseudoneonatal adrenoleukodystrophy). Endocrinology. 2012 Jun;153(6):2568-75. doi: 10.1210/en.2012-1137. Epub 2012 Apr 16. Citation on PubMed or Free article on PubMed Central
  • Ferdinandusse S, Denis S, Hogenhout EM, Koster J, van Roermund CW, IJlst L, Moser AB, Wanders RJ, Waterham HR. Clinical, biochemical, and mutational spectrum of peroxisomal acyl-coenzyme A oxidase deficiency. Hum Mutat. 2007 Sep;28(9):904-12. doi: 10.1002/humu.20535. Citation on PubMed
  • Kurian MA, Ryan S, Besley GT, Wanders RJ, King MD. Straight-chain acyl-CoA oxidase deficiency presenting with dysmorphia, neurodevelopmental autistic-type regression and a selective pattern of leukodystrophy. J Inherit Metab Dis. 2004;27(1):105-8. doi: 10.1023/b:boli.0000016687.88818.6d. Citation on PubMed
  • Su HM, Moser AB, Moser HW, Watkins PA. Peroxisomal straight-chain Acyl-CoA oxidase and D-bifunctional protein are essential for the retroconversion step in docosahexaenoic acid synthesis. J Biol Chem. 2001 Oct 12;276(41):38115-20. doi: 10.1074/jbc.M106326200. Epub 2001 Aug 10. Citation on PubMed
  • Suzuki Y, Iai M, Kamei A, Tanabe Y, Chida S, Yamaguchi S, Zhang Z, Takemoto Y, Shimozawa N, Kondo N. Peroxisomal acyl CoA oxidase deficiency. J Pediatr. 2002 Jan;140(1):128-30. doi: 10.1067/mpd.2002.120511. Citation on PubMed

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.