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Reviewed April 2009
What is the official name of the CHRNA4 gene?
The official name of this gene is “cholinergic receptor, nicotinic alpha 4.”
CHRNA4 is the gene's official symbol. The CHRNA4 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 CHRNA4 gene?
The CHRNA4 gene provides instructions for making one part (subunit) of a larger protein called a neuronal nicotinic acetylcholine receptor (nAChR). Each nAChR protein is made up of a combination of five subunits, usually two alpha (α) and three beta (β) subunits. Many different combinations are possible, and the characteristics of each nAChR protein depend on which subunits it contains. In the brain, nAChR proteins most commonly consist of two α4 subunits and three β2 subunits. The CHRNA4 gene is responsible for producing the α4 subunit.
In the brain, nAChR proteins are widely distributed and play an important role in chemical signaling between nerve cells (neurons). The nAChR proteins act as channels, allowing charged atoms (ions) including calcium, sodium, and potassium to cross the cell membrane. These channels open when attached to a brain chemical (neurotransmitter) called acetylcholine. The channels also open in response to nicotine, the addictive substance in tobacco.
Communication between neurons depends on neurotransmitters, which are released from one neuron and taken up by neighboring neurons. The release and uptake of these chemicals are tightly regulated to ensure that signals are passed efficiently and accurately between neurons. Researchers believe that nAChR channels play an important role in controlling the normal release and uptake of neurotransmitters.
A wide range of brain functions depend on nAChR channels, including sleep and arousal, fatigue, anxiety, attention, pain perception, and memory. The channels are also active before birth, which suggests that they are involved in early brain development. At least one drug that targets nAChR channels in the brain has been developed to help people quit smoking; other medications targeting these channels are under study for the treatment of schizophrenia, Alzheimer disease, and pain.
How are changes in the CHRNA4 gene related to health conditions?
Where is the CHRNA4 gene located?
Cytogenetic Location: 20q13.33
Molecular Location on chromosome 20: base pairs 63,343,310 to 63,361,396
The CHRNA4 gene is located on the long (q) arm of chromosome 20 at position 13.33.
More precisely, the CHRNA4 gene is located from base pair 63,343,310 to base pair 63,361,396 on chromosome 20.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about CHRNA4?
You and your healthcare professional may find the following resources about CHRNA4 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 CHRNA4 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 CHRNA4?
acetylcholine ; acids ; amino acid ; anxiety ; autosomal ; autosomal dominant ; calcium ; cell ; cell membrane ; dopamine ; epilepsy ; gene ; ions ; mutation ; neuron ; neurotransmitters ; nicotine ; nocturnal ; perception ; polymorphism ; potassium ; protein ; receptor ; schizophrenia ; sodium ; subunit
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (11 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.