Reviewed April 2009
What is the official name of the CHRNB2 gene?
The official name of this gene is “cholinergic receptor, nicotinic, beta 2 (neuronal).”
CHRNB2 is the gene's official symbol. The CHRNB2 gene is also known by other names, listed below.
What is the normal function of the CHRNB2 gene?
The CHRNB2 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 CHRNB2 gene is responsible for producing the β2 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 CHRNB2 gene related to health conditions?
- autosomal dominant nocturnal frontal lobe epilepsy - caused by mutations in the CHRNB2 gene
At least three mutations in the CHRNB2 gene have been identified in people with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). Each of these mutations changes a single protein building block (amino acid) in the β2 subunit of nAChR channels.
CHRNB2 mutations make nAChR channels more sensitive to the neurotransmitter acetylcholine, allowing the channels to open more easily than usual. The resulting increase in ion flow across the cell membrane alters the release of neurotransmitters, which changes signaling between neurons. Researchers believe that the overexcitement of certain neurons in the brain triggers the abnormal brain activity associated with seizures. It is unclear why the seizures seen in ADNFLE start in the frontal lobes of the brain and occur most often during sleep.
Where is the CHRNB2 gene located?
Cytogenetic Location: 1q21.3
Molecular Location on chromosome 1: base pairs 154,540,256 to 154,552,353
The CHRNB2 gene is located on the long (q) arm of chromosome 1 at position 21.3.
More precisely, the CHRNB2 gene is located from base pair 154,540,256 to base pair 154,552,353 on chromosome 1.
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 CHRNB2?
You and your healthcare professional may find the following resources about CHRNB2 helpful.
Educational resources - Information pages
- Basic Neurochemistry (sixth edition, 1998): Nicotinic Receptors (http://www.ncbi.nlm.nih.gov/books/NBK28261/)
- Molecular Cell Biology (fourth edition, 2000): All Five Subunits in the Nicotinic Acetylcholine Receptor Contribute to the Ion Channel (http://www.ncbi.nlm.nih.gov/books/NBK21586/)
- Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/books/NBK1169/)
Genetic Testing Registry - Repository of genetic test information
- GTR: Genetic tests for CHRNB2 (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=1141%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=(CHRNB2%5BTIAB%5D)%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%201800%20days%22%5Bdp%5D)
- OMIM - Genetic disorder catalog (http://omim.org/entry/118507)
Research Resources - Tools for researchers
- GeneCards (http://www.genecards.org/cgi-bin/carddisp.pl?id_type=entrezgene&id=1141)
- HUGO Gene Nomenclature Committee (http://www.genenames.org/data/hgnc_data.php?hgnc_id=1962)
- NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/1141)
What other names do people use for the CHRNB2 gene or gene products?
- Acetylcholine receptor, neuronal nicotinic, beta-2 subunit
- cholinergic receptor, nicotinic, beta polypeptide 2 (neuronal)
- neuronal nicotinic acetylcholine receptor beta 2
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 CHRNB2?
amino acid ;
autosomal dominant ;
cell membrane ;
You may find definitions for these and many other terms in the Genetics Home Reference
- Arneric SP, Holladay M, Williams M. Neuronal nicotinic receptors: a perspective on two decades of drug discovery research. Biochem Pharmacol. 2007 Oct 15;74(8):1092-101. Epub 2007 Jun 26. Review. (http://www.ncbi.nlm.nih.gov/pubmed/17662959?dopt=Abstract)
- Bertrand D, Elmslie F, Hughes E, Trounce J, Sander T, Bertrand S, Steinlein OK. The CHRNB2 mutation I312M is associated with epilepsy and distinct memory deficits. Neurobiol Dis. 2005 Dec;20(3):799-804. Epub 2005 Jun 17. (http://www.ncbi.nlm.nih.gov/pubmed/15964197?dopt=Abstract)
- Bertrand D, Picard F, Le Hellard S, Weiland S, Favre I, Phillips H, Bertrand S, Berkovic SF, Malafosse A, Mulley J. How mutations in the nAChRs can cause ADNFLE epilepsy. Epilepsia. 2002;43 Suppl 5:112-22. (http://www.ncbi.nlm.nih.gov/pubmed/12121305?dopt=Abstract)
- Bertrand S, Weiland S, Berkovic SF, Steinlein OK, Bertrand D. Properties of neuronal nicotinic acetylcholine receptor mutants from humans suffering from autosomal dominant nocturnal frontal lobe epilepsy. Br J Pharmacol. 1998 Oct;125(4):751-60. (http://www.ncbi.nlm.nih.gov/pubmed/9831911?dopt=Abstract)
- De Fusco M, Becchetti A, Patrignani A, Annesi G, Gambardella A, Quattrone A, Ballabio A, Wanke E, Casari G. The nicotinic receptor beta 2 subunit is mutant in nocturnal frontal lobe epilepsy. Nat Genet. 2000 Nov;26(3):275-6. (http://www.ncbi.nlm.nih.gov/pubmed/11062464?dopt=Abstract)
- di Corcia G, Blasetti A, De Simone M, Verrotti A, Chiarelli F. Recent advances on autosomal dominant nocturnal frontal lobe epilepsy: "understanding the nicotinic acetylcholine receptor (nAChR)". Eur J Paediatr Neurol. 2005;9(2):59-66. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15843070?dopt=Abstract)
- Hoda JC, Gu W, Friedli M, Phillips HA, Bertrand S, Antonarakis SE, Goudie D, Roberts R, Scheffer IE, Marini C, Patel J, Berkovic SF, Mulley JC, Steinlein OK, Bertrand D. Human nocturnal frontal lobe epilepsy: pharmocogenomic profiles of pathogenic nicotinic acetylcholine receptor beta-subunit mutations outside the ion channel pore. Mol Pharmacol. 2008 Aug;74(2):379-91. doi: 10.1124/mol.107.044545. Epub 2008 May 2. (http://www.ncbi.nlm.nih.gov/pubmed/18456869?dopt=Abstract)
- Marini C, Guerrini R. The role of the nicotinic acetylcholine receptors in sleep-related epilepsy. Biochem Pharmacol. 2007 Oct 15;74(8):1308-14. Epub 2007 Jun 23. Review. (http://www.ncbi.nlm.nih.gov/pubmed/17662253?dopt=Abstract)
- NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/1141)
- Phillips HA, Favre I, Kirkpatrick M, Zuberi SM, Goudie D, Heron SE, Scheffer IE, Sutherland GR, Berkovic SF, Bertrand D, Mulley JC. CHRNB2 is the second acetylcholine receptor subunit associated with autosomal dominant nocturnal frontal lobe epilepsy. Am J Hum Genet. 2001 Jan;68(1):225-31. Epub 2000 Dec 5. (http://www.ncbi.nlm.nih.gov/pubmed/11104662?dopt=Abstract)
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
See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.