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CHRNG gene

cholinergic receptor nicotinic gamma subunit

Normal Function

The CHRNG gene provides instructions for making the gamma (γ) protein component (subunit) of the acetylcholine receptor (AChR) protein. The AChR protein is found in the membrane of skeletal muscle cells and is critical for signaling between nerve and muscle cells. Signaling between these cells is necessary for movement. The AChR protein consists of five subunits, each of which is produced from a different gene. The subunits are assembled into the AChR protein in the endoplasmic reticulum, a cell structure involved in protein processing and transport, before being transported to the cell membrane. The γ subunit is found only in the fetal AChR protein. At about the thirty-third week of pregnancy, the γ subunit is replaced by the epsilon (ε) subunit, which is produced by the CHRNE gene, to form the adult AChR protein.

Health Conditions Related to Genetic Changes

Multiple pterygium syndrome

At least 14 mutations in the CHRNG gene have been found to cause multiple pterygium syndrome, a condition characterized by webbing of the skin (pterygium) and a lack of muscle movement (akinesia) before birth. These mutations include replacing, adding, or deleting DNA building blocks (nucleotides). CHRNG gene mutations result in an impaired or missing γ subunit. The severity of the CHRNG gene mutation influences the severity of the condition. Typically, mutations that prevent the production of any γ subunit will result in lethal multiple pterygium syndrome, which is fatal before birth, while mutations that allow the production of some γ subunit will lead to the milder form of this condition called multiple pterygium syndrome, Escobar type. A shortage of a functional γ subunit prevents the fetal AChR protein from being assembled or properly placed in the muscle cell membrane. As a result, the fetal AChR protein cannot function and the communication between nerve and muscle cells in the developing fetus is impaired. A lack of signaling between nerve and muscle cells leads to akinesia and pterygium before birth, and many of the other signs and symptoms of multiple pterygium syndrome.

More About This Health Condition

Other Names for This Gene

  • acetylcholine gamma muscle receptor subunit
  • acetylcholine receptor subunit gamma
  • acetylcholine receptor, muscle, gamma subunit
  • cholinergic gamma nicotinic receptor
  • cholinergic receptor, nicotinic gamma
  • cholinergic receptor, nicotinic, gamma
  • cholinergic receptor, nicotinic, gamma (muscle)
  • cholinergic receptor, nicotinic, gamma polypeptide

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


  • Hoffmann K, Muller JS, Stricker S, Megarbane A, Rajab A, Lindner TH, Cohen M, Chouery E, Adaimy L, Ghanem I, Delague V, Boltshauser E, Talim B, Horvath R, Robinson PN, Lochmuller H, Hubner C, Mundlos S. Escobar syndrome is a prenatal myasthenia caused by disruption of the acetylcholine receptor fetal gamma subunit. Am J Hum Genet. 2006 Aug;79(2):303-12. doi: 10.1086/506257. Epub 2006 Jun 20. Citation on PubMed or Free article on PubMed Central
  • Michalk A, Stricker S, Becker J, Rupps R, Pantzar T, Miertus J, Botta G, Naretto VG, Janetzki C, Yaqoob N, Ott CE, Seelow D, Wieczorek D, Fiebig B, Wirth B, Hoopmann M, Walther M, Korber F, Blankenburg M, Mundlos S, Heller R, Hoffmann K. Acetylcholine receptor pathway mutations explain various fetal akinesia deformation sequence disorders. Am J Hum Genet. 2008 Feb;82(2):464-76. doi: 10.1016/j.ajhg.2007.11.006. Citation on PubMed or Free article on PubMed Central
  • Morgan NV, Brueton LA, Cox P, Greally MT, Tolmie J, Pasha S, Aligianis IA, van Bokhoven H, Marton T, Al-Gazali L, Morton JE, Oley C, Johnson CA, Trembath RC, Brunner HG, Maher ER. Mutations in the embryonal subunit of the acetylcholine receptor (CHRNG) cause lethal and Escobar variants of multiple pterygium syndrome. Am J Hum Genet. 2006 Aug;79(2):390-5. doi: 10.1086/506256. Epub 2006 Jun 20. Citation on PubMed or Free article on PubMed Central

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.