Skip Navigation
Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed August 2012

What is the official name of the SOD1 gene?

The official name of this gene is “superoxide dismutase 1, soluble.”

SOD1 is the gene's official symbol. The SOD1 gene is also known by other names, listed below.

What is the normal function of the SOD1 gene?

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. Superoxide radicals can damage cells if too many accumulate within cells. Superoxide radicals are byproducts of normal cell processes, particularly energy-producing reactions, and must be broken down regularly.

How are changes in the SOD1 gene related to health conditions?

amyotrophic lateral sclerosis - caused by mutations in the SOD1 gene

At least 170 mutations in the SOD1 gene have been found to cause amyotrophic lateral sclerosis (ALS), a condition characterized by progressive movement problems and muscle wasting. 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 4 in the enzyme. (This mutation is written as Ala4Val or A4V.) The A4V mutation is typically associated with more severe signs and symptoms.

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

Where is the SOD1 gene located?

Cytogenetic Location: 21q22.11

Molecular Location on chromosome 21: base pairs 31,659,622 to 31,668,931

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The SOD1 gene is located on the long (q) arm of chromosome 21 at position 22.11.

The SOD1 gene is located on the long (q) arm of chromosome 21 at position 22.11.

More precisely, the SOD1 gene is located from base pair 31,659,622 to base pair 31,668,931 on chromosome 21.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about SOD1?

You and your healthcare professional may find the following resources about SOD1 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the SOD1 gene or gene products?

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

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding SOD1?

acids ; alanine ; amino acid ; cell ; enzyme ; gene ; mutation ; oxidative stress ; oxygen ; protein ; sclerosis ; soluble ; stress ; superoxide dismutase ; toxic ; valine ; wasting

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • 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. Epub 2006 Apr 4. Review. (
  • Gene Review: Amyotrophic Lateral Sclerosis Overview (
  • NCBI Gene (
  • 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. Epub 2006 May 22. Review. (
  • 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. Epub 2007 Jan 5. Review. (
  • Valentine JS, Doucette PA, Zittin Potter S. Copper-zinc superoxide dismutase and amyotrophic lateral sclerosis. Annu Rev Biochem. 2005;74:563-93. Review. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: August 2012
Published: February 1, 2016