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Genetics Home Reference: your guide to understanding genetic conditions
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SCNN1G

Reviewed March 2013

What is the official name of the SCNN1G gene?

The official name of this gene is “sodium channel, non-voltage-gated 1, gamma subunit.”

SCNN1G is the gene's official symbol. The SCNN1G gene is also known by other names, listed below.

What is the normal function of the SCNN1G gene?

The SCNN1G gene provides instructions for making one piece, the gamma subunit, of a protein complex called the epithelial sodium channel (ENaC). The channel is composed of alpha, beta, and gamma subunits, each of which is produced from a different gene. These channels are found at the surface of certain cells called epithelial cells in many tissues of the body, including the kidneys, lungs, and sweat glands. The ENaC channel transports sodium into cells.

In the kidney, ENaC channels open in response to signals that sodium levels in the blood are too low, which allows sodium to flow into cells. From the kidney cells, this sodium is returned to the bloodstream (a process called reabsorption) rather than being removed from the body in urine. In addition to regulating the amount of sodium in the body, the flow of sodium ions helps control the movement of water in tissues. For example, ENaC channels in lung cells help regulate the amount of fluid in the lungs.

Does the SCNN1G gene share characteristics with other genes?

The SCNN1G gene belongs to a family of genes called SC (sodium channels).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.

How are changes in the SCNN1G gene related to health conditions?

Liddle syndrome - caused by mutations in the SCNN1G gene

At least 5 mutations in the SCNN1G gene can cause a condition known as Liddle syndrome. People with Liddle syndrome have high blood pressure (hypertension) and low levels of potassium in their blood (hypokalemia), often beginning in childhood. Mutations in the SCNN1G gene associated with Liddle syndrome lead to the production of an abnormally short gamma subunit protein. These changes affect an important region of the gamma subunit protein involved in signaling for its breakdown (degradation). As a result of the mutations, the protein is not degraded, and more ENaC channels remain at the cell surface. The increase in channels at the cell surface allows the reabsorption of excess sodium (followed by water), which leads to hypertension. Reabsorption of sodium into the blood is linked with removal of potassium from the blood, so excess sodium reabsorption leads to hypokalemia.

pseudohypoaldosteronism type 1 - caused by mutations in the SCNN1G gene

Mutations in the SCNN1G gene are involved in a condition called pseudohypoaldosteronism type 1 (PHA1). This condition typically begins in infancy and is characterized by low levels of sodium (hyponatremia) and high levels of potassium (hyperkalemia) in the blood, and severe dehydration due to the loss of excess sodium and fluid in urine. In particular, SCNN1G gene mutations are involved in autosomal recessive PHA1, a severe form of the condition that does not improve with age.

Most mutations in the SCNN1G gene lead to an abnormally short gamma subunit protein. These mutations result in reduced or absent ENaC channel activity. As a result, sodium reabsorption is impaired, leading to hyponatremia and other signs and symptoms of autosomal recessive PHA1. The reduced function of ENaC channels in lung epithelial cells leads to excess fluid in the lungs and recurrent lung infections.

other disorders - caused by mutations in the SCNN1G gene

Some people with cystic fibrosis-like syndrome have a mutation or a normal gene variation (polymorphism) in the SCNN1G gene. People with cystic fibrosis-like syndrome (also known as atypical cystic fibrosis or bronchiectasis with or without elevated sweat chloride type 3) have signs and symptoms that resemble those of cystic fibrosis, including breathing problems and lung infections. However, changes in the gene most commonly associated with cystic fibrosis, CFTR, cannot explain development of the condition. It is thought that a mutation or gene variation in the SCNN1G gene can disrupt sodium transport and fluid balance, which leads to the signs and symptoms of cystic fibrosis-like syndrome.

Where is the SCNN1G gene located?

Cytogenetic Location: 16p12

Molecular Location on chromosome 16: base pairs 23,182,718 to 23,216,879

The SCNN1G gene is located on the short (p) arm of chromosome 16 at position 12.

The SCNN1G gene is located on the short (p) arm of chromosome 16 at position 12.

More precisely, the SCNN1G gene is located from base pair 23,182,718 to base pair 23,216,879 on chromosome 16.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about SCNN1G?

You and your healthcare professional may find the following resources about SCNN1G 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 SCNN1G gene or gene products?

  • amiloride-sensitive epithelial sodium channel gamma subunit
  • amiloride-sensitive sodium channel gamma-subunit
  • amiloride-sensitive sodium channel subunit gamma
  • BESC3
  • ENaCg
  • ENaCgamma
  • ENaC gamma subunit
  • epithelial Na(+) channel subunit gamma
  • gamma-ENaC
  • gamma-NaCH
  • nonvoltage-gated sodium channel 1 subunit gamma
  • SCNEG
  • SCNNG_HUMAN
  • sodium channel, nonvoltage-gated 1, gamma

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding SCNN1G?

atypical ; autosomal ; autosomal recessive ; breakdown ; bronchiectasis ; cell ; channel ; chloride ; degradation ; dehydration ; epithelial ; fibrosis ; gene ; hyperkalemia ; hypertension ; hypokalemia ; hyponatremia ; ions ; kidney ; mutation ; Na ; polymorphism ; potassium ; protein ; recessive ; sodium ; sodium channel ; subunit ; syndrome ; voltage

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Abriel H, Loffing J, Rebhun JF, Pratt JH, Schild L, Horisberger JD, Rotin D, Staub O. Defective regulation of the epithelial Na+ channel by Nedd4 in Liddle's syndrome. J Clin Invest. 1999 Mar;103(5):667-73. (http://www.ncbi.nlm.nih.gov/pubmed/10074483?dopt=Abstract)
  • Azad AK, Rauh R, Vermeulen F, Jaspers M, Korbmacher J, Boissier B, Bassinet L, Fichou Y, des Georges M, Stanke F, De Boeck K, Dupont L, Balascáková M, Hjelte L, Lebecque P, Radojkovic D, Castellani C, Schwartz M, Stuhrmann M, Schwarz M, Skalicka V, de Monestrol I, Girodon E, Férec C, Claustres M, Tümmler B, Cassiman JJ, Korbmacher C, Cuppens H. Mutations in the amiloride-sensitive epithelial sodium channel in patients with cystic fibrosis-like disease. Hum Mutat. 2009 Jul;30(7):1093-103. doi: 10.1002/humu.21011. (http://www.ncbi.nlm.nih.gov/pubmed/19462466?dopt=Abstract)
  • Bogdanović R, Kuburović V, Stajić N, Mughal SS, Hilger A, Ninić S, Prijić S, Ludwig M. Liddle syndrome in a Serbian family and literature review of underlying mutations. Eur J Pediatr. 2012 Mar;171(3):471-8. doi: 10.1007/s00431-011-1581-8. Epub 2011 Sep 29. Review. (http://www.ncbi.nlm.nih.gov/pubmed/21956615?dopt=Abstract)
  • Canessa CM, Schild L, Buell G, Thorens B, Gautschi I, Horisberger JD, Rossier BC. Amiloride-sensitive epithelial Na+ channel is made of three homologous subunits. Nature. 1994 Feb 3;367(6462):463-7. (http://www.ncbi.nlm.nih.gov/pubmed/8107805?dopt=Abstract)
  • Chang SS, Grunder S, Hanukoglu A, Rösler A, Mathew PM, Hanukoglu I, Schild L, Lu Y, Shimkets RA, Nelson-Williams C, Rossier BC, Lifton RP. Mutations in subunits of the epithelial sodium channel cause salt wasting with hyperkalaemic acidosis, pseudohypoaldosteronism type 1. Nat Genet. 1996 Mar;12(3):248-53. (http://www.ncbi.nlm.nih.gov/pubmed/8589714?dopt=Abstract)
  • Chen SY, Bhargava A, Mastroberardino L, Meijer OC, Wang J, Buse P, Firestone GL, Verrey F, Pearce D. Epithelial sodium channel regulated by aldosterone-induced protein sgk. Proc Natl Acad Sci U S A. 1999 Mar 2;96(5):2514-9. (http://www.ncbi.nlm.nih.gov/pubmed/10051674?dopt=Abstract)
  • Hansson JH, Nelson-Williams C, Suzuki H, Schild L, Shimkets R, Lu Y, Canessa C, Iwasaki T, Rossier B, Lifton RP. Hypertension caused by a truncated epithelial sodium channel gamma subunit: genetic heterogeneity of Liddle syndrome. Nat Genet. 1995 Sep;11(1):76-82. (http://www.ncbi.nlm.nih.gov/pubmed/7550319?dopt=Abstract)
  • Masilamani S, Kim GH, Mitchell C, Wade JB, Knepper MA. Aldosterone-mediated regulation of ENaC alpha, beta, and gamma subunit proteins in rat kidney. J Clin Invest. 1999 Oct;104(7):R19-23. (http://www.ncbi.nlm.nih.gov/pubmed/10510339?dopt=Abstract)
  • Mutesa L, Azad AK, Verhaeghe C, Segers K, Vanbellinghen JF, Ngendahayo L, Rusingiza EK, Mutwa PR, Rulisa S, Koulischer L, Cassiman JJ, Cuppens H, Bours V. Genetic analysis of Rwandan patients with cystic fibrosis-like symptoms: identification of novel cystic fibrosis transmembrane conductance regulator and epithelial sodium channel gene variants. Chest. 2009 May;135(5):1233-42. doi: 10.1378/chest.08-2246. Epub 2008 Nov 18. (http://www.ncbi.nlm.nih.gov/pubmed/19017867?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/6340)
  • OMIM: SODIUM CHANNEL, NONVOLTAGE-GATED 1, GAMMA SUBUNIT (http://omim.org/entry/600761)
  • Snyder PM, Price MP, McDonald FJ, Adams CM, Volk KA, Zeiher BG, Stokes JB, Welsh MJ. Mechanism by which Liddle's syndrome mutations increase activity of a human epithelial Na+ channel. Cell. 1995 Dec 15;83(6):969-78. (http://www.ncbi.nlm.nih.gov/pubmed/8521520?dopt=Abstract)
  • Warnock DG. Liddle syndrome: genetics and mechanisms of Na+ channel defects. Am J Med Sci. 2001 Dec;322(6):302-7. Review. (http://www.ncbi.nlm.nih.gov/pubmed/11780687?dopt=Abstract)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: March 2013
Published: August 25, 2014