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Genetics Home Reference: your guide to understanding genetic conditions
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SCNN1A

Reviewed December 2011

What is the official name of the SCNN1A gene?

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

SCNN1A is the gene's official symbol. The SCNN1A gene is also known by other names, listed below.

What is the normal function of the SCNN1A gene?

The SCNN1A gene provides instructions for making one piece, the alpha 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 take sodium into cells in response to signals that sodium levels in the body are too low. From the kidney cells, this sodium is returned to the bloodstream rather than being removed from the body (a process called reabsorption). 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 SCNN1A gene share characteristics with other genes?

The SCNN1A gene belongs to a family of genes called SCN (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 SCNN1A gene related to health conditions?

pseudohypoaldosteronism type 1 - caused by mutations in the SCNN1A gene

At least a dozen mutations in the SCNN1A gene cause 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. In particular, SCNN1A gene mutations are involved in autosomal recessive PHA1, a severe form of the condition that does not improve with age.

Most mutations in the SCNN1A gene result in a shortened alpha subunit protein of the ENaC channel. Other mutations delete a small piece of DNA or change a single protein building block (amino acid) in the alpha subunit protein. SCNN1A gene mutations lead to 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 - associated with the SCNN1A gene

Some people with cystic fibrosis-like syndrome have a mutation or a normal gene variation (polymorphism) in the SCNN1A gene. People with cystic fibrosis-like syndrome (also known as atypical cystic fibrosis or bronchiectasis with or without elevated sweat chloride type 2) 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 SCNN1A gene can disrupt sodium transport and fluid balance, which leads to the signs and symptoms of cystic fibrosis-like syndrome.

Where is the SCNN1A gene located?

Cytogenetic Location: 12p13

Molecular Location on chromosome 12: base pairs 6,456,008 to 6,486,522

The SCNN1A gene is located on the short (p) arm of chromosome 12 at position 13.

The SCNN1A gene is located on the short (p) arm of chromosome 12 at position 13.

More precisely, the SCNN1A gene is located from base pair 6,456,008 to base pair 6,486,522 on chromosome 12.

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 SCNN1A?

You and your healthcare professional may find the following resources about SCNN1A helpful.

  • Genetic Testing Registry - Repository of genetic test information

    • GTR: Genetic tests for SCNN1A (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=6337%5Bgeneid%5D)

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

  • PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/pubmed?term=(SCNN1A%5BTIAB%5D)%20OR%20((alpha-ENaC%5BTIAB%5D)%20OR%20(alpha-NaCH%5BTIAB%5D)%20OR%20(amiloride-sensitive%20epithelial%20sodium%20channel%20alpha%20subunit%5BTIAB%5D)%20OR%20(ENaCa%5BTIAB%5D)%20OR%20(ENaCalpha%5BTIAB%5D)%20OR%20(SCNN1%5BTIAB%5D))%20AND%20((Genes%5BMH%5D)%20OR%20(Genetic%20Phenomena%5BMH%5D))%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%201440%20days%22%5Bdp%5D)

  • OMIM - Genetic disorder catalog

    • BRONCHIECTASIS WITH OR WITHOUT ELEVATED SWEAT CHLORIDE 2 (http://omim.org/entry/613021)
    • SODIUM CHANNEL, NONVOLTAGE-GATED 1, ALPHA SUBUNIT (http://omim.org/entry/600228)

  • Research Resources - Tools for researchers

    • Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://atlasgeneticsoncology.org/Genes/GC_SCNN1A.html)
    • Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/6337)
    • GeneCards (http://www.genecards.org/cgi-bin/carddisp.pl?id_type=entrezgene&id=6337)
    • HUGO Gene Nomenclature Committee (http://www.genenames.org/data/hgnc_data.php?hgnc_id=10599)

What other names do people use for the SCNN1A gene or gene products?

  • alpha-ENaC
  • alpha-NaCH
  • amiloride-sensitive epithelial sodium channel alpha subunit
  • amiloride-sensitive sodium channel subunit alpha
  • BESC2
  • ENaCa
  • ENaCalpha
  • epithelial Na(+) channel subunit alpha
  • FLJ21883
  • nasal epithelial sodium channel alpha subunit
  • nonvoltage-gated sodium channel 1 subunit alpha
  • SCNEA
  • SCNN1
  • SCNNA_HUMAN
  • sodium channel, nonvoltage-gated 1 alpha

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 SCNN1A?

amino acid ; atypical ; autosomal ; autosomal recessive ; bronchiectasis ; channel ; chloride ; dehydration ; DNA ; epithelial ; fibrosis ; gene ; hyperkalemia ; 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

  • 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)
  • 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)
  • Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/6337)
  • 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)
  • OMIM: SODIUM CHANNEL, NONVOLTAGE-GATED 1, ALPHA SUBUNIT (http://omim.org/entry/600228)

 

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: December 2011
Published: June 17, 2013