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ACADS gene

acyl-CoA dehydrogenase short chain

Normal Function

The ACADS gene provides instructions for making an enzyme called short-chain acyl-CoA dehydrogenase (SCAD). This enzyme functions within mitochondria, the energy-producing centers within cells. SCAD is essential for fatty acid oxidation, which is the multistep process that breaks down (metabolizes) fats and converts them to energy.

SCAD is required to metabolize a group of fats called short-chain fatty acids. These fatty acids are found in some foods and are also produced when larger fatty acids are metabolized. Fatty acids are a major source of energy for the heart and muscles. During periods without food (fasting), fatty acids are also an important energy source for the liver and other tissues.

Health Conditions Related to Genetic Changes

Short-chain acyl-CoA dehydrogenase deficiency

More than 55 mutations in the ACADS gene have been found to cause short-chain acyl-CoA dehydrogenase (SCAD) deficiency. Almost all of these mutations change single protein building blocks (amino acids) in the SCAD enzyme. These mutations prevent the enzyme from properly metabolizing short-chain fatty acids. As a result, these fats are not converted into energy, which can lead to the characteristic signs and symptoms of this disorder, including lack of energy (lethargy), low blood glucose (hypoglycemia), poor muscle tone (hypotonia), and weakness.

Researchers have also identified two common variations (polymorphisms) in the ACADS gene that each change one amino acid in the SCAD enzyme. Unlike other changes in the ACADS gene, these polymorphisms do not cause SCAD deficiency but may increase a person's risk of developing this disorder. One of these polymorphisms replaces the amino acid arginine with the amino acid tryptophan at protein position 147 (written as Arg147Trp or R147W). The other polymorphism switches the amino acid glycine with the amino acid serine at protein position 185 (written as Gly185Ser or G185S). Other genetic and environmental factors likely influence the risk of developing SCAD deficiency when a person carries either of these polymorphisms.

More About This Health Condition

Other Names for This Gene

  • ACAD3
  • acyl-CoA dehydrogenase, C-2 to C-3 short chain
  • acyl-Coenzyme A dehydrogenase, C-2 to C-3 short chain precursor
  • Butyryl dehydrogenase
  • Butyryl-CoA dehydrogenase
  • SCAD
  • Unsaturated acyl-CoA reductase

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


  • Gregersen N, Andresen BS, Corydon MJ, Corydon TJ, Olsen RK, Bolund L, Bross P. Mutation analysis in mitochondrial fatty acid oxidation defects: Exemplified by acyl-CoA dehydrogenase deficiencies, with special focus on genotype-phenotype relationship. Hum Mutat. 2001 Sep;18(3):169-89. doi: 10.1002/humu.1174. Citation on PubMed
  • Jethva R, Bennett MJ, Vockley J. Short-chain acyl-coenzyme A dehydrogenase deficiency. Mol Genet Metab. 2008 Dec;95(4):195-200. doi: 10.1016/j.ymgme.2008.09.007. Epub 2008 Nov 5. Citation on PubMed or Free article on PubMed Central
  • Kim SH, Park HD, Sohn YB, Park SW, Cho SY, Ji S, Kim SJ, Choi EW, Kim CH, Ko AR, Yeau S, Paik KH, Jin DK. Mutations of ACADS gene associated with short-chain acyl-coenzyme A dehydrogenase deficiency. Ann Clin Lab Sci. 2011 Fall;41(1):84-8. Citation on PubMed
  • Nagan N, Kruckeberg KE, Tauscher AL, Bailey KS, Rinaldo P, Matern D. The frequency of short-chain acyl-CoA dehydrogenase gene variants in the US population and correlation with the C(4)-acylcarnitine concentration in newborn blood spots. Mol Genet Metab. 2003 Apr;78(4):239-46. doi: 10.1016/s1096-7192(03)00034-9. Citation on PubMed
  • Pedersen CB, Kolvraa S, Kolvraa A, Stenbroen V, Kjeldsen M, Ensenauer R, Tein I, Matern D, Rinaldo P, Vianey-Saban C, Ribes A, Lehnert W, Christensen E, Corydon TJ, Andresen BS, Vang S, Bolund L, Vockley J, Bross P, Gregersen N. The ACADS gene variation spectrum in 114 patients with short-chain acyl-CoA dehydrogenase (SCAD) deficiency is dominated by missense variations leading to protein misfolding at the cellular level. Hum Genet. 2008 Aug;124(1):43-56. doi: 10.1007/s00439-008-0521-9. Epub 2008 Jun 4. Citation on PubMed
  • Schmidt SP, Corydon TJ, Pedersen CB, Bross P, Gregersen N. Misfolding of short-chain acyl-CoA dehydrogenase leads to mitochondrial fission and oxidative stress. Mol Genet Metab. 2010 Jun;100(2):155-62. doi: 10.1016/j.ymgme.2010.03.009. Epub 2010 Mar 19. Citation on PubMed
  • Schmidt SP, Corydon TJ, Pedersen CB, Vang S, Palmfeldt J, Stenbroen V, Wanders RJ, Ruiter JP, Gregersen N. Toxic response caused by a misfolding variant of the mitochondrial protein short-chain acyl-CoA dehydrogenase. J Inherit Metab Dis. 2011 Apr;34(2):465-75. doi: 10.1007/s10545-010-9255-7. Epub 2010 Dec 18. Citation on PubMed or Free article on PubMed Central
  • Shirao K, Okada S, Tajima G, Tsumura M, Hara K, Yasunaga S, Ohtsubo M, Hata I, Sakura N, Shigematsu Y, Takihara Y, Kobayashi M. Molecular pathogenesis of a novel mutation, G108D, in short-chain acyl-CoA dehydrogenase identified in subjects with short-chain acyl-CoA dehydrogenase deficiency. Hum Genet. 2010 Jun;127(6):619-28. doi: 10.1007/s00439-010-0822-7. Epub 2010 Apr 8. Citation on PubMed
  • van Maldegem BT, Waterham HR, Duran M, van der Vlies M, van Woerden CS, Bobu LL, Wanders RJ, Wijburg FA. The 625G>A SCAD gene variant is common but not associated with increased C4-carnitine in newborn blood spots. J Inherit Metab Dis. 2005;28(4):557-62. doi: 10.1007/s10545-005-0557-0. Citation on PubMed
  • Young SP, Matern D, Gregersen N, Stevens RD, Bali D, Liu HM, Koeberl DD, Millington DS. A comparison of in vitro acylcarnitine profiling methods for the diagnosis of classical and variant short chain acyl-CoA dehydrogenase deficiency. Clin Chim Acta. 2003 Nov;337(1-2):103-13. doi: 10.1016/j.cccn.2003.07.006. 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.