Pseudocholinesterase Deficiency: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Pseudocholinesterase Deficiency?
An anesthesiologist, a doctor who gives anesthesia (medicine that keeps you from feeling pain during surgery) and watches your breathing, is often involved. A geneticist, a doctor who treats inherited conditions, can help families. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is pseudocholinesterase deficiency?
Pseudocholinesterase deficiency is also called butyrylcholinesterase deficiency. It makes a person extra sensitive to some substances. These include the medicines succinylcholine and mivacurium. These medicines may be given during general anesthesia. General anesthesia is used in major surgery. It causes a short period of unconsciousness.
These medicines relax the muscles you use to move. They also relax the muscles you use to breathe. The body normally breaks these medicines down within a few minutes. With this condition, they stay active longer than usual.
Symptoms
Most people with this condition have no other signs or symptoms. It is usually found only after a person has an unusual reaction to one of these substances.
After these medicines, a person may not be able to move or breathe alone for a few hours. The breathing muscles can become paralyzed, so the person stops breathing. A person who never gets these anesthetic drugs may never know about the condition.
People with this condition may also react more strongly to other substances:
- Cocaine.
- Procaine, a local anesthetic. Local anesthetics numb a small area of the body.
- Some farm pesticides.
Causes and who gets it
Changes in the BCHE gene can cause this condition. The gene has instructions for making an enzyme called pseudocholinesterase. The liver makes this enzyme, and it travels in the blood. Some gene changes make an enzyme that does not work well. Other changes stop the body from making any of the enzyme.
When gene changes cause it, it is inherited in an autosomal recessive pattern. This means both copies of the gene in each cell must have a change. About 1 in 500 people have a change in only one copy of the gene. They clear some substances more slowly than usual. But it typically does not take them as long as people with changes in both copies.
Some cases are not caused by gene changes and are not inherited. In these cases, other factors change how well the enzyme works. These factors include pregnancy, older age, and long-lasting infections. They also include kidney, liver, or heart disease, poor nutrition, major burns, cancer, and some prescription medicines.
The condition occurs in about 1 in 3,200 to 1 in 5,000 people. It is more common in males than in females. It is also more common in the Persian Jewish community. It is more common in some people of Alaskan Native descent and in White people of European descent.
How doctors diagnose it
Testing can be done before surgery to find out if a person has this condition. One test is a blood test called serum cholinesterase. It checks levels of two substances that help the nerves work. One of them is pseudocholinesterase. The test needs a blood sample. You do not need special steps to prepare. Doctors may order this test before a person gets anesthesia with succinylcholine.
A low level can come from a deficiency passed down in families. Other causes of a low level include long-lasting infection, poor nutrition, and liver damage.
Treatment
If a person stops breathing for a long time during surgery, a breathing machine can help. The machine is used until the medicines clear from the body. This is called mechanical ventilation. Testing before surgery can show the condition ahead of time. People with this condition should warn their relatives to get tested before surgery. It is a genetic disorder.
When to see a doctor
Talk to a doctor before any surgery if a relative died for unknown reasons during surgery. A person who cannot breathe alone after these medicines must be supported with a breathing machine until the medicines clear from the body.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either kind of doctor can review your health history and arrange testing. They can also refer you to a geneticist.
Common questions
Is pseudocholinesterase deficiency inherited?
It can be, but not always. When gene changes cause it, both copies of the gene in each cell must have a change.
Do people with this condition have symptoms every day?
No, people with this condition typically have no other signs or symptoms. It is usually not found until a person has an unusual reaction to certain medicines.
Can a blood test show this condition?
Yes, a blood test called serum cholinesterase checks levels of pseudocholinesterase. A low level can mean a deficiency passed down in families. Other problems, such as liver damage, can also cause it.
Should my relatives be tested too?
Yes, relatives should get tested before surgery. This is a genetic disorder.
Sources
- MedlinePlus Genetics - Pseudocholinesterase deficiency
- National Organization for Rare Disorders - Pseudocholinesterase Deficiency
- MedlinePlus - Cholinesterase blood test
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
