BCHE rs1799807: What Your Genotype Means
The rs1799807 variant is a single-nucleotide polymorphism located in the BCHE gene that defines the classic 'atypical' (A) variant of pseudocholinesterase. Individuals carrying this alteration produce an altered enzyme with significantly reduced binding affinity for specific muscle relaxants used during anesthesia, such as succinylcholine and mivacurium. Under normal physiological circumstances, carriers experience no health issues, but exposure to these specific drugs can lead to extended paralysis and prolonged postanesthetic apnea.
What each genotype means
Typical enzyme activity
This genotype represents the most common form of the BCHE gene, often referred to as the wild-type or normal variant. Individuals with this profile typically produce functional butyrylcholinesterase enzyme at expected levels. As with any medical procedure, always inform your anesthesiologist of your genetic profile before receiving neuromuscular blocking agents.
This is the most common genotype found in the vast majority of the global population.
Reduced enzyme activity
This genotype indicates you carry one copy of the atypical (A) variant, which may result in reduced butyrylcholinesterase enzyme activity. While you may clear certain medications like succinylcholine or mivacurium slightly slower than those with the typical genotype, it typically does not cause the severe, prolonged paralysis seen in individuals with two copies of the variant. Please discuss this result with your clinician or pharmacist before undergoing procedures requiring neuromuscular blockers.
Carried by roughly 3% to 4% of people of European ancestry, though it is significantly rarer in East Asian and African populations.
Increased sensitivity to medications
This genotype means you carry two copies of the atypical (A) variant, which is associated with significantly reduced or altered butyrylcholinesterase enzyme function. This can lead to a decreased ability to break down specific neuromuscular blocking drugs, potentially resulting in prolonged paralysis and apnea following anesthesia. It is essential to share this information with your healthcare providers and anesthesiologist well in advance of any surgery.
This genotype is rare, occurring in approximately 1 in 2,500 to 5,000 individuals in European populations and is even less common in other ancestries.
What Is rs1799807 and Where Is It Located?
The rs1799807 polymorphism sits on chromosome 3 within exon 2 of the BCHE gene (at cDNA position c.293T>C, historically referenced in different protein numbering systems as p.Asp70Gly, p.Asp90Gly, or p.Asp98Gly). It represents a missense substitution where a thymine is replaced by a cytosine on the coding strand (or an adenine to guanine swap depending on strand orientation). This change substitutes an aspartic acid with a glycine residue near the active site gorge of the circulating enzyme. Pharmacogenetically, this allele is designated as the atypical or 'A' variant (BCHE*A). Unlike null mutations that eliminate the production of the enzyme altogether, rs1799807 is classified as a qualitative variant. The body produces normal quantities of the circulating protein, but the structural change markedly impairs the enzyme's affinity for choline esters and confers biochemical resistance to inhibition by dibucaine, an established clinical diagnostic marker.
The Biological Role of the BCHE Gene
The BCHE gene provides instructions for synthesizing butyrylcholinesterase, also known as pseudocholinesterase or plasma cholinesterase. Produced primarily by hepatocytes in the liver, this enzyme circulates freely in the bloodstream and metabolizes a wide range of neuroactive esters, organophosphates, and pharmacological agents. In perioperative medicine, pseudocholinesterase is the primary enzyme responsible for rapidly breaking down short-acting depolarizing neuromuscular blocking agents, most notably succinylcholine, as well as the nondepolarizing agent mivacurium. Under ordinary circumstances, the wild-type enzyme metabolizes succinylcholine within minutes, permitting patients to resume spontaneous respiration swiftly after tracheal intubation. However, when the enzyme's binding pocket is structurally altered by the atypical variant, its catalytic clearance of these medications drops dramatically, leaving the drugs active at the neuromuscular junction for far longer than anticipated.
Clinical Research and Evidence Strength
The relationship between rs1799807 and altered drug metabolism represents one of the foundational discoveries in modern pharmacogenetics, documented since the mid-twentieth century and detailed on resources like [PharmGKB](https://www.pharmgkb.org/rsid/rs1799807) and [MedlinePlus Genetics](https://medlineplus.gov/genetics/gene/bche/). Multiple clinical studies demonstrate that homozygous carriers (CC) who receive standard doses of succinylcholine or mivacurium face a substantial risk of prolonged neuromuscular blockade, frequently leading to apnea lasting several hours instead of the usual 5 to 10 minutes. Heterozygous carriers (CT) typically experience mild or subclinical delays in recovery unless they concurrently carry an additional variant in trans, such as the common Kalow (K) variant (rs1803274) or a rare fluoride-resistant (F) allele. While the biochemical mechanism and clinical consequences in surgical settings are clearly established, broad evidence regarding routine universal pre-operative screening remains limited, meaning testing is most often conducted reactively following an adverse anesthetic event or a known family history.
Population Frequency and Ancestry Patterns
The minor allele (C) for rs1799807 is found across diverse global ancestries, though its prevalence varies considerably by geographic background. In individuals of European ancestry, the minor allele frequency is estimated at approximately 1.5% to 2.0%, corresponding to roughly 1 in 25 to 1 in 35 people being heterozygous carriers and approximately 1 in 2,500 to 1 in 3,500 being homozygous. By comparison, the atypical allele is significantly less common among individuals of East Asian and African ancestries, where reported frequencies are typically under 0.5%. Population surveys in multi-ethnic cohorts show that compound heterozygosity—combining rs1799807 with other functional BCHE alleles like rs1803274—further diversifies clinical risk profiles across different ancestral communities.
Navigating Your Genetic Results Responsibly
Discovering an atypical allele in personal genomic data is primarily useful for anesthesia preparedness rather than general health optimization. Carrying rs1799807 causes no baseline symptoms, chronic disease, or day-to-day functional impairment, as pseudocholinesterase deficiency is clinically silent in the absence of triggering pharmaceuticals. Consequently, genetic results must never be interpreted as an acute medical crisis. Instead, individuals aware of carrying one or two atypical alleles should share this documentation with their surgical team, anesthesiologist, or clinical pharmacist prior to any elective procedure or emergency intervention. Anesthesia providers routinely employ alternative muscle relaxants (such as rocuronium or vecuronium, which rely on different metabolic pathways) or maintain mechanical ventilation until standard drug effects fully subside, preventing unexpected perioperative complications.
How common is this variant?
The minor C allele has a frequency of approximately 1.5% to 2.0% in European populations, making homozygous individuals occur in roughly 1 in 2,500 to 3,500 births; it is considerably rarer in East Asian and African ancestries.
Frequently asked questions
What is the BCHE rs1799807 variant?
The rs1799807 variant is a single-base change in the BCHE gene that produces the 'atypical' form of the pseudocholinesterase enzyme. This alteration impairs the enzyme's ability to quickly break down specific muscle relaxants like succinylcholine, potentially causing prolonged muscle paralysis after anesthesia.
Does carrying the rs1799807 variant cause everyday symptoms?
No, pseudocholinesterase deficiency caused by rs1799807 is completely silent during daily life and does not impact normal physical health, endurance, or life expectancy. Health effects only occur when a carrier receives specific anesthesia medications, local ester anesthetics, or certain agricultural organophosphates.
What happens if someone with the CC genotype receives succinylcholine?
Instead of recovering muscle control and unassisted breathing within 5 to 10 minutes, a person homozygous for the atypical allele may experience continued paralysis and apnea lasting between two to eight hours. Anesthesiologists manage this safely by keeping the patient sedated and on a mechanical ventilator until the drug clears or by reversing it with alternative clinical strategies.
Can I test for this condition without genetic sequencing?
Yes, laboratory medicine has long utilized a biochemical blood test called a dibucaine number test alongside overall pseudocholinesterase activity measurements. Dibucaine inhibits the typical enzyme far more effectively than the atypical form, allowing clinicians to deduce atypical BCHE activity even without direct DNA sequencing.
What should I tell my surgical team if I carry this variant?
You should inform your surgeon, anesthesiologist, and clinical pharmacist ahead of time that you carry a BCHE variant associated with pseudocholinesterase deficiency. Armed with this knowledge, your anesthesia care team can select alternative non-depolarizing muscle relaxants that do not rely on the BCHE pathway.
Sources & further reading
Educational information only, last refreshed 9/5/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs1799807?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29Related variants in BCHE
A variant in the BCHE gene associated with butyrylcholinesterase activity levels.
Encodes the atypical A variant (Asp70Gly) of butyrylcholinesterase which drastically prolongs muscle paralysis after standard doses of mivacurium or succinylcholine.
Defines the BCHE fluoride-resistant (F2, p.Gly418Arg) allele that leads to impaired hydrolysis of mivacurium and succinylcholine, increasing prolonged post-anesthesia apnea risk.
Defines the BCHE fluoride-resistant (F1, p.Thr267Met) allele linked to reduced pseudocholinesterase activity and delayed recovery from succinylcholine-induced muscle relaxation.
Commonly known as the BCHE atypical variant (Asp70Gly), this single nucleotide change reduces pseudocholinesterase enzyme activity, affecting drug metabolism in obstetric anesthesia and reproduction-related surgical procedures.