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PubMed This is a summary of 15 peer-reviewed journal articles Updated
Anesthesiology

What is Hereditary Butyrylcholinesterase Deficiency?

At a Glance

Hereditary butyrylcholinesterase (BChE) deficiency is a silent genetic trait that prevents the body from breaking down certain anesthesia drugs. While harmless in daily life, it causes prolonged paralysis during surgery, requiring temporary ventilator support until the medication wears off.

This condition is not a “disease” in the traditional sense; in your day-to-day life, you are completely healthy [1][2]. It only matters when you are given specific medications during a medical procedure [3].

A Silent Genetic Trait

Normally, your body produces an enzyme called butyrylcholinesterase (BChE). Its job is to break down certain chemicals in the body [4]. For most people, this enzyme is highly active. However, in people with this deficiency, the enzyme is either missing or doesn’t work correctly because of a variation in the BCHE gene [5][6].

Because this enzyme doesn’t have a vital role in your daily health, you could go your entire life without ever knowing you have it [7]. It remains “silent” until you encounter specific drugs used in anesthesia—most commonly succinylcholine or mivacurium [3][8].

Why It Is Discovered During Surgery

During many surgeries, anesthesiologists use “muscle relaxants” to temporarily paralyze your muscles so they don’t move during the procedure and to make it easier to place a breathing tube [3].

  • In a typical person: These drugs are broken down by the BChE enzyme within minutes [9].
  • In someone with the deficiency: The drugs stay in the system for anywhere from 1 to 8 hours depending on your specific genetic variant, because the body cannot “turn them off” [10].

This leads to prolonged apnea, which is a medical term for being unable to breathe on your own while the muscle relaxant is still active [11].

The Experience: Terrifying but Manageable

If you were the one on the operating table, the experience might have been frightening, especially if you began to regain consciousness while your muscles were still paralyzed. This is why doctors prioritize keeping you sedated (asleep) until the drug wears off [11].

While it feels like a crisis, it is a very manageable situation for an anesthesia team:

  • Supportive Care: The primary treatment is simply to keep you on a ventilator (a breathing machine) to do the breathing for you [9][10].
  • Safety: As long as the medical team provides oxygen and keeps you comfortable, there is no long-term damage to your brain or organs [12].
  • Resolution: The drugs will eventually wear off on their own as they are slowly cleared by other processes in your body [11].

How Common Is It?

The incidence of this condition varies depending on your genetic background:

  • The Most Severe Form: Affects approximately 1 in 2,500 to 1 in 3,500 people of Caucasian descent [5].
  • Moderate Risk: As many as 1 in 25 to 1 in 50 people (about 4-8% of some populations) may have a milder version that causes a slightly longer recovery time than average [5][5].

What Happens Next?

Now that this trait has been identified, you have the power to prevent it from ever happening again. Your doctors may use biochemical tests to find your Dibucaine number (a measure of how well your enzyme works) or use genetic testing to confirm which variant you have [13][1].

In the future, you must simply inform any surgical team about your condition. They will use different muscle relaxants that your body can break down, making surgery just as safe for you as it is for anyone else [14][15]. (If you want to know more about the testing process, see The BCHE Gene and Diagnosis).

Common questions in this guide

What happens during surgery if I have BChE deficiency?
If you receive certain muscle relaxants like succinylcholine, your body cannot break them down quickly. This causes prolonged paralysis and an inability to breathe on your own, requiring the medical team to keep you sedated and on a ventilator until the medication wears off.
How do doctors diagnose BChE deficiency?
Doctors typically use a blood test to check your Dibucaine number, which measures how well the enzyme is working. They may also recommend genetic testing to identify the specific variation in your BCHE gene.
Will I have any symptoms in my daily life?
No, hereditary butyrylcholinesterase deficiency is a silent trait. In your normal day-to-day life, you will feel completely healthy and experience no symptoms unless you are exposed to specific anesthesia drugs.
Are future surgeries safe for me?
Yes, future surgeries are perfectly safe as long as you inform your surgical and anesthesia team about your diagnosis. They will use different muscle relaxants that your body can process normally without prolonged side effects.
Should my family members be tested for this condition?
Because this is a hereditary condition caused by genetic variations, your blood relatives may also have it. It is important to inform your family members so they can discuss testing with their doctors before having any surgeries.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What specific genetic variant or biochemical 'Dibucaine number' do I have, and how does it affect the severity of my reaction?
  2. 2.Has this diagnosis been officially added to my electronic medical record so that it triggers an alert for any future procedures?
  3. 3.Were you using quantitative neuromuscular monitoring during my surgery, and what did it show about how long the drugs lasted in my system?
  4. 4.Which specific muscle relaxants must I avoid in the future, and what safe alternatives are available?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (15)
  1. 1

    Timing of blood sampling for butyrylcholinesterase phenotyping in patients with prolonged neuromuscular block after mivacurium or suxamethonium.

    Mintjens N, Brummans R, Soetens F, et al.

    Acta anaesthesiologica Scandinavica 2021; (65(2)):182-187 doi:10.1111/aas.13718.

    PMID: 33010031
  2. 2

    Butyrylcholinesterase deficiency.

    Delacour H, Dedome E, Courcelle S, et al.

    Annales de biologie clinique 2016; (74(3)):279-85 doi:10.1684/abc.2016.1141.

    PMID: 27237801
  3. 3

    Suspected Pseudocholinesterase Deficiency During Left Thyroid Lobectomy and Isthmusectomy: A Case Report.

    Boleyn J, McLaury M, Wieman S

    South Dakota medicine : the journal of the South Dakota State Medical Association 2024; (77(6)):266-269.

    PMID: 39013099
  4. 4

    Hereditary Pseudocholinesterase Deficiency and Succinylcholine: Historical Perspective, Therapeutic Implications, and Future Considerations.

    Nguyen JQ, Paetznick C, Donnelly RS

    Pharmacotherapy 2025; (45(9)):600-620 doi:10.1002/phar.70048.

    PMID: 40778538
  5. 5

    Genetic Testing for BCHE Variants Identifies Patients at Risk of Prolonged Neuromuscular Blockade in Response to Succinylcholine.

    Zhu GD, Dawson E, Huskey A, et al.

    Pharmacogenomics and personalized medicine 2020; (13()):405-414 doi:10.2147/PGPM.S263741.

    PMID: 33061533
  6. 6

    Human butyrylcholinesterase polymorphism: Molecular modeling.

    Lushchekina S, Delacour H, Lockridge O, Masson P

    The International journal of risk & safety in medicine 2015; (27 Suppl 1()):S80-1 doi:10.3233/JRS-150699.

    PMID: 26639724
  7. 7

    Pseudocholinesterase Deficiency - Is Succinylcholine Still Needed to Facilitate Endotracheal Intubation?

    Kurnutala LN, Rugnath N

    Cureus 2020; (12(9)):e10721 doi:10.7759/cureus.10721.

    PMID: 33150117
  8. 8

    Pseudocholinesterase Deficiency Considerations: A Case Study.

    Cornelius BW, Jacobs TM

    Anesthesia progress 2020; (67(3)):177-184 doi:10.2344/anpr-67-03-16.

    PMID: 32992329
  9. 9

    Prolonged neuromuscular block associated with cholinesterase deficiency.

    Zhang C, Cao H, Wan ZG, Wang J

    Medicine 2018; (97(52)):e13714 doi:10.1097/MD.0000000000013714.

    PMID: 30593143
  10. 10

    Pseudocholinesterase deficiency in ophthalmology: a systematic review.

    Cheng T, Curley M, Barmettler A

    Orbit (Amsterdam, Netherlands) 2024; (43(3)):429-437 doi:10.1080/01676830.2023.2166083.

    PMID: 36661099
  11. 11

    Delayed recovery from paralysis associated with plasma cholinesterase deficiency.

    Zhou W, Lv S

    SpringerPlus 2016; (5(1)):1887 doi:10.1186/s40064-016-3561-y.

    PMID: 27843744
  12. 12

    Effects of repetitive prolonged breath-hold in elite divers on myocardial fibrosis and cerebral morphology.

    Doerner J, Eichhorn L, Luetkens JA, et al.

    European journal of radiology 2018; (103()):13-18 doi:10.1016/j.ejrad.2018.03.020.

    PMID: 29803378
  13. 13

    Genotype-phenotype relationships in butyrylcholinesterase deficiency: a systematic review.

    Snak de Souza CD, Ibarra Moreno CA, Riazi S, Hopkins PM

    British journal of anaesthesia 2026; (137(2)):450-459 doi:10.1016/j.bja.2026.03.056.

    PMID: 42120224
  14. 14

    Premature awakening and underuse of neuromuscular monitoring in a registry of patients with butyrylcholinesterase deficiency.

    Thomsen JL, Nielsen CV, Palmqvist DF, Gätke MR

    British journal of anaesthesia 2015; (115 Suppl 1()):i89-i94 doi:10.1093/bja/aev103.

    PMID: 26174307
  15. 15

    Early Neurophysiological Monitoring of Train of Four Assists in the Detection of Pseudocholinesterase Deficiency.

    Celis V, Gandhi S, Overzet K

    The Neurodiagnostic journal 2025; (65(1)):57-63 doi:10.1080/21646821.2024.2401641.

    PMID: 39331762

This page provides general educational information about hereditary butyrylcholinesterase deficiency. Always consult with an anesthesiologist or medical geneticist regarding your specific genetic risks before any surgical procedure.

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