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SOD1 gene

superoxide dismutase 1

Normal Function

The SOD1 gene provides instructions for making an enzyme called superoxide dismutase, which is abundant in cells throughout the body. This enzyme attaches (binds) to molecules of copper and zinc to break down toxic, charged oxygen molecules called superoxide radicals. The molecules are byproducts of normal cell processes, and they must be broken down regularly to avoid damaging cells.

Health Conditions Related to Genetic Changes

Amyotrophic lateral sclerosis

At least 200 mutations in the SOD1 gene have been found to cause amyotrophic lateral sclerosis (ALS), a condition characterized by progressive muscle weakness, a loss of muscle mass, and an inability to control movement. Most of these mutations change one of the protein building blocks (amino acids) in the superoxide dismutase enzyme. About half of all Americans with ALS caused by SOD1 gene mutations have a particular mutation that replaces the amino acid alanine with the amino acid valine at position 5 in the enzyme, written as Ala5Val or A5V. (Because of variations in the ways amino acids are counted in proteins, this mutation is sometimes called Ala4Val or A4V.) ALS caused by the A5V mutation is generally associated with a shorter life expectancy compared with ALS caused by other genetic mutations.

ALS is caused by the death of nerve cells that control muscle movement (motor neurons). It is unclear why these cells are particularly sensitive to SOD1 gene mutations. Researchers have suggested several ways in which the altered enzyme may cause the death of motor neurons. These possibilities include an increase in harmful superoxide radicals, increased production of other types of toxic radicals, increased cell death, or accumulation of clumps (aggregates) of misfolded superoxide dismutase that may be toxic to cells.

More About This Health Condition

Other Names for This Gene

  • ALS1
  • Cu/Zn superoxide dismutase
  • indophenoloxidase A
  • IPOA
  • superoxide dismutase 1, soluble
  • superoxide dismutase 1, soluble (amyotrophic lateral sclerosis 1 (adult))
  • superoxide dismutase, cystolic
  • superoxide dismutase-1, soluble

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


  • Barber SC, Mead RJ, Shaw PJ. Oxidative stress in ALS: a mechanism of neurodegeneration and a therapeutic target. Biochim Biophys Acta. 2006 Nov-Dec;1762(11-12):1051-67. doi: 10.1016/j.bbadis.2006.03.008. Epub 2006 Apr 4. Citation on PubMed
  • Bertolin C, D'Ascenzo C, Querin G, Gaiani A, Boaretto F, Salvoro C, Vazza G, Angelini C, Cagnin A, Pegoraro E, Soraru G, Mostacciuolo ML. Improving the knowledge of amyotrophic lateral sclerosis genetics: novel SOD1 and FUS variants. Neurobiol Aging. 2014 May;35(5):1212.e7-1212.e10. doi: 10.1016/j.neurobiolaging.2013.10.093. Epub 2013 Oct 29. Citation on PubMed
  • Rakhit R, Chakrabartty A. Structure, folding, and misfolding of Cu,Zn superoxide dismutase in amyotrophic lateral sclerosis. Biochim Biophys Acta. 2006 Nov-Dec;1762(11-12):1025-37. doi: 10.1016/j.bbadis.2006.05.004. Epub 2006 May 22. Citation on PubMed
  • Shaw BF, Valentine JS. How do ALS-associated mutations in superoxide dismutase 1 promote aggregation of the protein? Trends Biochem Sci. 2007 Feb;32(2):78-85. doi: 10.1016/j.tibs.2006.12.005. Epub 2007 Jan 5. Citation on PubMed
  • Siddique N, Siddique T. Amyotrophic Lateral Sclerosis Overview. 2001 Mar 23 [updated 2023 Sep 28]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from Citation on PubMed
  • Tsang CK, Liu Y, Thomas J, Zhang Y, Zheng XF. Superoxide dismutase 1 acts as a nuclear transcription factor to regulate oxidative stress resistance. Nat Commun. 2014 Mar 19;5:3446. doi: 10.1038/ncomms4446. Citation on PubMed or Free article on PubMed Central
  • Valentine JS, Doucette PA, Zittin Potter S. Copper-zinc superoxide dismutase and amyotrophic lateral sclerosis. Annu Rev Biochem. 2005;74:563-93. doi: 10.1146/annurev.biochem.72.121801.161647. Citation on PubMed

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