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

SCN gene family

Reviewed December 2011

What are the SCN genes?

Genes in the SCN family provide instructions for making sodium channels. These channels transport positively charged sodium atoms (sodium ions) into cells. Sodium channels play key roles in a cell's ability to generate and transmit electrical signals.

Sodium channels are made up of several protein components (subunits), each of which is produced from a particular gene. The α (alpha) subunit is the largest and most important component of each sodium channel. It forms the hole (pore) through which sodium ions can flow. The α subunit interacts with one or more smaller β (beta) subunits, which help regulate the channel's function and interact with various other proteins inside and outside the cell.

Sodium channels have critical functions in several different tissues. For example, these channels are abundant in heart (cardiac) muscle, where they play a major role in maintaining a normal heart rhythm. Sodium channels are also found in muscles used for movement (skeletal muscles), where they help control muscle tensing (contraction) and relaxation. Additionally, sodium channels are essential for the normal function of the nervous system. These channels help transmit electrical signals within and between nerve cells in the brain and throughout the body.

Mutations in genes in the SCN family cause disorders affecting the heart, skeletal muscles, and nervous system. In the heart, abnormal sodium channel function causes several diseases characterized by abnormal heart rhythms (arrhythmias). Changes in sodium channels in skeletal muscle cells are responsible for disorders that cause muscle weakness and episodes of paralysis. Altered sodium channel function in the nervous system can lead to several types of childhood epilepsy, a rare familial form of migraines, and pain disorders.

Several medications work by targeting sodium channels. These medications include certain drugs used to block the sensation of pain (anesthetics), anti-seizure drugs, and drugs used to treat abnormal heartbeats (antiarrhythmics).

Which genes are included in the SCN gene family?

The HUGO Gene Nomenclature Committee (HGNC) provides a list of genes in the SCN family (

Genetics Home Reference summarizes the normal function and health implications of these members of the SCN gene family: SCN1A, SCN4A, SCN5A, SCN9A, SCN10A, SCNN1A, SCNN1B, and SCNN1G.

What conditions are related to genes in the SCN gene family?

Genetics Home Reference includes these conditions related to genes in the SCN gene family:

  • Brugada syndrome
  • congenital insensitivity to pain
  • congenital myasthenic syndrome
  • erythromelalgia
  • familial dilated cardiomyopathy
  • familial hemiplegic migraine
  • hyperkalemic periodic paralysis
  • hypokalemic periodic paralysis
  • Liddle syndrome
  • malignant migrating partial seizures of infancy
  • paramyotonia congenita
  • paroxysmal extreme pain disorder
  • potassium-aggravated myotonia
  • pseudohypoaldosteronism type 1
  • Romano-Ward syndrome
  • sick sinus syndrome
  • small fiber neuropathy

Where can I find additional information about the SCN gene family?

You may find the following resources about the SCN gene family helpful.

  • Voltage Gated Sodium Channels ( (University of Washington)
  • About Arrhythmia ( (American Heart Association)
  • Neuromuscular Disease Center, Washington University (

What glossary definitions help with understanding the SCN gene family?

action potential ; anesthetics ; cardiac ; cell ; channel ; contraction ; epilepsy ; familial ; gene ; ions ; muscle cells ; Na ; nervous system ; protein ; seizure ; skeletal muscle ; sodium ; sodium channel ; subunit ; voltage

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


These sources were used to develop the Genetics Home Reference summary for the SCN gene family.

  • Yu FH, Catterall WA. Overview of the voltage-gated sodium channel family. Genome Biol. 2003;4(3):207. Epub 2003 Feb 24. Review. (
  • Diss JK, Fraser SP, Djamgoz MB. Voltage-gated Na+ channels: multiplicity of expression, plasticity, functional implications and pathophysiological aspects. Eur Biophys J. 2004 May;33(3):180-93. Epub 2004 Feb 12. Review. (
  • Koopmann TT, Bezzina CR, Wilde AA. Voltage-gated sodium channels: action players with many faces. Ann Med. 2006;38(7):472-82. Review. (
  • George AL Jr. Inherited disorders of voltage-gated sodium channels. J Clin Invest. 2005 Aug;115(8):1990-9. 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: December 2011
Published: July 21, 2014