|A service of the U.S. National Library of Medicine®|
On this page:
Reviewed January 2015
What is the official name of the CNGA3 gene?
The official name of this gene is “cyclic nucleotide gated channel alpha 3.”
CNGA3 is the gene's official symbol. The CNGA3 gene is also known by other names, listed below.
Read more about gene names and symbols on the About page.
What is the normal function of the CNGA3 gene?
The CNGA3 gene provides instructions for making one part (the alpha subunit) of the cone photoreceptor cyclic nucleotide-gated (CNG) channel. These channels are found exclusively in light-detecting (photoreceptor) cells called cones, which are located in a specialized tissue at the back of the eye known as the retina. Cones provide vision in bright light (daylight vision), including color 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 (cations) into cells. In cones, CNG channels remain open under dark conditions, allowing cations to flow in. When light enters the eye, it triggers the closure of these channels, stopping the inward flow of cations. This change in cation transport alters the cone's electrical charge, which ultimately generates a signal that is interpreted by the brain as vision. This process of translating light into an electrical signal is called phototransduction.
Does the CNGA3 gene share characteristics with other genes?
The CNGA3 gene belongs to a family of genes called CNG (cyclic nucleotide-regulated 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? in the Handbook.
How are changes in the CNGA3 gene related to health conditions?
Where is the CNGA3 gene located?
Cytogenetic Location: 2q11.2
Molecular Location on chromosome 2: base pairs 98,346,155 to 98,399,154
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The CNGA3 gene is located on the long (q) arm of chromosome 2 at position 11.2.
More precisely, the CNGA3 gene is located from base pair 98,346,155 to base pair 98,399,154 on chromosome 2.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about CNGA3?
You and your healthcare professional may find the following resources about CNGA3 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 CNGA3 gene or gene products?
See How are genetic conditions and genes named? in the Handbook.
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding CNGA3?
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (10 links)
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.