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BCHE
butyrylcholinesterase
The BCHE gene provides instructions for making the butyrylcholinesterase enzyme, which plays a crucial role in breaking down certain medications and toxic substances in the body. The BCHE gene is responsible for producing the enzyme butyrylcholinesterase, also known as pseudocholinesterase.
BCHE is located on the long (q) arm of chromosome 3, at band 3q26.1. Arm ratio per GRCh38 - banding schematic.
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Overview
The BCHE gene encodes for butyrylcholinesterase, an enzyme produced in the liver that circulates throughout the bloodstream. This enzyme is vital for the breakdown of certain substances, including specific medications given during general anaesthesia, as well as some environmental toxins.
Variations within the BCHE gene can lead to altered enzyme activity, potentially affecting how an individual responds to these substances. Understanding the BCHE gene's role is particularly important in pharmacogenomics, as it can influence drug metabolism.
What the gene does
The butyrylcholinesterase enzyme, encoded by the BCHE gene, performs several critical functions within the body. Its primary role involves the hydrolysis, or breakdown, of choline esters. Notably, it metabolises succinylcholine and mivacurium, muscle relaxants often administered during general anaesthesia.
Beyond drug metabolism, butyrylcholinesterase also acts as a detoxifying agent, helping to neutralise various toxic compounds. This includes certain agricultural pesticides, recreational drugs, and naturally occurring toxins like solanine found in green potato skins. Research also suggests a potential role for pseudocholinesterase in the development and maturation of nerve cells within the brain.
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Chromosome location
The BCHE gene is located on chromosome 3, specifically at position 3q26.1. This region defines its precise address within the human genome. The gene spans several thousand base pairs and contains multiple exons that are transcribed and translated into the butyrylcholinesterase enzyme.
Protein structure
The butyrylcholinesterase protein, encoded by the BCHE gene, consists of 602 amino acids. Domain architecture has not been experimentally characterised in detail for this protein.
Key variants
Variations, often referred to as variants or mutations, within the BCHE gene can alter the function or production of the butyrylcholinesterase enzyme. Some variants may lead to an enzyme with reduced activity, while others might prevent the body from producing the enzyme altogether. These genetic differences can influence an individual's response to certain drugs and toxins.
Sample of pathogenic variants
10 pathogenic / likely-pathogenic variants from ClinVar, ranked by review status (expert-panel-reviewed first). This is a sample; recurrent founder variants in a specific population may not appear here - see the full ClinVar listing via the link above.
| Variant (HGVS) | Protein change | Classification | Evidence | Associated condition |
|---|---|---|---|---|
c.1004T>C | p.Leu335Pro | Pathogenic/Likely pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
c.100del | p.Ile34fs | Pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
c.1027dup | p.Thr343fs | Pathogenic/Likely pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
c.1072T>A | p.Leu358Ile | Pathogenic/Likely pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
c.1177G>C | p.Gly393Arg | Pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
c.1240C>T | p.Arg414Cys | Pathogenic/Likely pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
c.1354C>T | p.Arg452Ter | Pathogenic/Likely pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
c.1584T>A | p.Tyr528Ter | Pathogenic/Likely pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
c.428G>A | p.Gly143Asp | Pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
c.435delinsAG | p.Phe146fs | Pathogenic | ★★☆☆ | Deficiency of butyrylcholinesterase |
Evidence stars indicate ClinVar review status. Individual variant interpretation should always be performed by a qualified clinical laboratory - many variants remain classified as Variants of Uncertain Significance (VUS) pending more research.
Associated conditions
Variants in the BCHE gene are associated with pseudocholinesterase deficiency. This condition results in heightened sensitivity to specific medications, such as succinylcholine and mivacurium, which are muscle relaxants used in general anaesthesia. Individuals with this deficiency may experience prolonged effects of these drugs.
No disease links recorded for this gene in our reference set.
Inheritance pattern
Conditions caused by pathogenic BCHE variants typically follow autosomal recessive inheritance.
When both parents are carriers, each child has a 25% chance of being affected, 50% of being a carrier, and 25% of being unaffected.
UK clinical status
Frequently asked questions
What is the main function of the BCHE gene?
The BCHE gene provides instructions for making the butyrylcholinesterase enzyme, which primarily breaks down certain medications used in general anaesthesia, such as succinylcholine and mivacurium, and helps detoxify various toxic substances.
What happens if someone has a BCHE gene variant?
A variant in the BCHE gene can lead to pseudocholinesterase deficiency, meaning the enzyme may not function correctly or may be produced in insufficient amounts. This can cause increased sensitivity and prolonged effects from certain muscle relaxant medications.
Is BCHE testing relevant for medical procedures?
Yes, testing the BCHE gene can be relevant before certain medical procedures requiring general anaesthesia, particularly those involving muscle relaxants like succinylcholine or mivacurium. Knowing an individual's BCHE status can help anaesthetists tailor medication dosages to prevent adverse reactions.
References
- Garcia DF, Oliveira TG, Molfetta GA. Biochemical and genetic analysis of butyrylcholinesterase (BChE) in a family, due to prolonged neuromuscular blockade after the use of succinylcholine. Genetics and molecular biology. 2011. PMID: 21637541
- Howard TD, Hsu FC, Grzywacz JG. Evaluation of candidate genes for cholinesterase activity in farmworkers exposed to organophosphorus pesticides: association of single nucleotide polymorphisms in BCHE. Environmental health perspectives. 2010. PMID: 20529763
- Zelinski T, Coghlan G, Mauthe J. Molecular basis of succinylcholine sensitivity in a prairie Hutterite kindred and genetic characterization of the region containing the BCHE gene. Molecular genetics and metabolism. 2007. PMID: 17166756
- Gätke MR, Bundgaard JR, Viby-Mogensen J. Two novel mutations in the BCHE gene in patients with prolonged duration of action of mivacurium or succinylcholine during anaesthesia. Pharmacogenetics and genomics. 2007. PMID: 18075469
- Levano S, Ginz H, Siegemund M. Genotyping the butyrylcholinesterase in patients with prolonged neuromuscular block after succinylcholine. Anesthesiology. 2005. PMID: 15731589
- Yen T, Nightingale BN, Burns JC. Butyrylcholinesterase (BCHE) genotyping for post-succinylcholine apnea in an Australian population. Clinical chemistry. 2003. PMID: 12881446