cyclic nucleotide gated channel subunit alpha 3
Last updated 14 Aug 2025
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The CNGA3 gene provides instructions for making one part (the alpha subunit) of the cyclic nucleotide-gated (CNG) channel. These channels are found exclusively in light-sensing (photoreceptor) cells called cones, which are located in a specialized tissue at the back of the eye (retina). Cones provide colour vision and vision in bright light (daytime vision). Other photoreceptor cells, called rods, provide vision in low light (night vision).
Normal function
The CNGA3 gene provides instructions for making one part (the alpha subunit) of the cyclic nucleotide-gated (CNG) channel. These channels are found exclusively in light-sensing (photoreceptor) cells called cones, which are located in a specialized tissue at the back of the eye (retina). Cones provide colour vision and vision in bright light (daytime vision). Other photoreceptor cells, called rods, provide vision in low light (night vision).
CNG channels are openings in the cell membrane that transport positively charged atoms (ions) into cells. The CNG channels in cones remain open in low light, allowing ions to flow in. When light enters the eye, these channels close, stopping the flow of ions. This change in ion transport alters the cone's electrical charge, which ultimately generates a signal. This signal is sent to the brain, where it combines with other visual information and is interpreted as vision. The process of translating light into an electrical signal is called phototransduction.
Conditions referring to this gene or chromosome
Other names
ACHM2
cyclic nucleotide-gated channel, alpha-3
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Further reading and references
- cyclic nucleotide gated channel subunit alpha 3; MedlinePlus, National Library of Medicine.
- Gill JS, Georgiou M, Kalitzeos A, Moore AT, Michaelides M. Progressive cone and cone-rod dystrophies: clinical features, molecular genetics and prospects for therapy. Br J Ophthalmol. 2019 Jan 24;103(5):711-20. doi: 10.1136/bjophthalmol-2018-313278. Online ahead of print.
- Hirji N, Aboshiha J, Georgiou M, Bainbridge J, Michaelides M. Achromatopsia: clinical features, molecular genetics, animal models and therapeutic options. Ophthalmic Genet. 2018 Apr;39(2):149-157. doi: 10.1080/13816810.2017.1418389. Epub 2018 Jan 5.
- Johnson S, Michaelides M, Aligianis IA, Ainsworth JR, Mollon JD, Maher ER, Moore AT, Hunt DM. Achromatopsia caused by novel mutations in both CNGA3 and CNGB3. J Med Genet. 2004 Feb;41(2):e20. doi: 10.1136/jmg.2003.011437. No abstract available.
- Koeppen K, Reuter P, Ladewig T, Kohl S, Baumann B, Jacobson SG, Plomp AS, Hamel CP, Janecke AR, Wissinger B. Dissecting the pathogenic mechanisms of mutations in the pore region of the human cone photoreceptor cyclic nucleotide-gated channel. Hum Mutat. 2010 Jul;31(7):830-9. doi: 10.1002/humu.21283.
- Kohl S, Jagle H, Wissinger B, Zobor D. Achromatopsia. 2004 Jun 24 [updated 2018 Sep 20]. In: Adam MP, Bick S, Mirzaa GM, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2026. Available from http://www.ncbi.nlm.nih.gov/books/NBK1418/
- Kohl S, Marx T, Giddings I, Jagle H, Jacobson SG, Apfelstedt-Sylla E, Zrenner E, Sharpe LT, Wissinger B. Total colourblindness is caused by mutations in the gene encoding the alpha-subunit of the cone photoreceptor cGMP-gated cation channel. Nat Genet. 1998 Jul;19(3):257-9. doi: 10.1038/935.
- Li S, Huang L, Xiao X, Jia X, Guo X, Zhang Q. Identification of CNGA3 mutations in 46 families: common cause of achromatopsia and cone-rod dystrophies in Chinese patients. JAMA Ophthalmol. 2014 Sep;132(9):1076-83. doi: 10.1001/jamaophthalmol.2014.1032.
- Michalakis S, Gerhardt M, Rudolph G, Priglinger S, Priglinger C. Achromatopsia: Genetics and Gene Therapy. Mol Diagn Ther. 2022 Jan;26(1):51-59. doi: 10.1007/s40291-021-00565-z. Epub 2021 Dec 3.
- Patel KA, Bartoli KM, Fandino RA, Ngatchou AN, Woch G, Carey J, Tanaka JC. Transmembrane S1 mutations in CNGA3 from achromatopsia 2 patients cause loss of function and impaired cellular trafficking of the cone CNG channel. Invest Ophthalmol Vis Sci. 2005 Jul;46(7):2282-90. doi: 10.1167/iovs.05-0179.
- Reuter P, Koeppen K, Ladewig T, Kohl S, Baumann B, Wissinger B; Achromatopsia Clinical Study Group. Mutations in CNGA3 impair trafficking or function of cone cyclic nucleotide-gated channels, resulting in achromatopsia. Hum Mutat. 2008 Oct;29(10):1228-36. doi: 10.1002/humu.20790.
- Sun W, Zhang Q. Diseases associated with mutations in CNGA3: Genotype-phenotype correlation and diagnostic guideline. Prog Mol Biol Transl Sci. 2019;161:1-27. doi: 10.1016/bs.pmbts.2018.10.002. Epub 2018 Nov 23.
- Thiadens AA, Roosing S, Collin RW, van Moll-Ramirez N, van Lith-Verhoeven JJ, van Schooneveld MJ, den Hollander AI, van den Born LI, Hoyng CB, Cremers FP, Klaver CC. Comprehensive analysis of the achromatopsia genes CNGA3 and CNGB3 in progressive cone dystrophy. Ophthalmology. 2010 Apr;117(4):825-30.e1. doi: 10.1016/j.ophtha.2009.09.008. Epub 2010 Jan 15.
- Trankner D, Jagle H, Kohl S, Apfelstedt-Sylla E, Sharpe LT, Kaupp UB, Zrenner E, Seifert R, Wissinger B. Molecular basis of an inherited form of incomplete achromatopsia. J Neurosci. 2004 Jan 7;24(1):138-47. doi: 10.1523/JNEUROSCI.3883-03.2004.
- Wissinger B, Gamer D, Jagle H, Giorda R, Marx T, Mayer S, Tippmann S, Broghammer M, Jurklies B, Rosenberg T, Jacobson SG, Sener EC, Tatlipinar S, Hoyng CB, Castellan C, Bitoun P, Andreasson S, Rudolph G, Kellner U, Lorenz B, Wolff G, Verellen-Dumoulin C, Schwartz M, Cremers FP, Apfelstedt-Sylla E, Zrenner E, Salati R, Sharpe LT, Kohl S. CNGA3 mutations in hereditary cone photoreceptor disorders. Am J Hum Genet. 2001 Oct;69(4):722-37. doi: 10.1086/323613. Epub 2001 Aug 30.
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