Medically reviewed by Debnath Chatterjee, MD, FAAP, FASA, and Randall Clark, MD, FASA, July 30, 2026

Venezuelan Lineage and Rare Anesthesia Risk

If you or your child has Venezuelan lineage through the mother’s side of the family, tell your anesthesiologist before surgery or any procedure requiring anesthesia. Physicians, health agencies, and international experts have found a rare genetic mutation that may impact your care. Sharing your family history can help your Anesthesia Care Team plan the safest approach for you or your child.

What is this rare anesthesia risk for patients of Venezuelan lineage?

The American Society of Anesthesiologists (ASA) is closely monitoring reports of a very rare medical condition linked to serious complications from general anesthesia. These complications have arisen in some healthy children and adults of Venezuelan lineage.

In these cases, patients experienced serious brain and nervous system complications after routine general anesthesia. Some patients suffered serious brain injury, and some died.

Doctors and researchers are still learning about these cases, but in some affected patients, testing found a rare change in mitochondrial DNA. This change involves a gene called MT-ND4. You may also hear it referred to as the ND4 gene mutation, MT-ND4 mutation, or mitochondrial DNA variant.

This mutation has been associated with Venezuelan lineage on the mother’s side of a person’s family. Most people with Venezuelan lineage on their mother’s side will not experience these complications from anesthesia. But because the reported cases have been so serious, ASA encourages patients who may be at risk to speak with their anesthesiologist before surgery.

What is the ND4 gene mutation?

The ND4 gene, also called MT-ND4, is part of mitochondrial DNA, which is passed down maternally—that is, through the mother.

Mitochondria are tiny structures inside your cells that help your body produce energy. The brain, heart, and muscles rely heavily on this energy.

In some patients, testing has found a specific change in the MT-ND4 gene. Researchers are studying whether this mutation may make some patients more sensitive to certain anesthesia medicines. This may include some inhaled anesthesia gases used during general anesthesia.

Who may be at risk, and why does Venezuelan lineage matter?

Based on what is known now, concern about these rare anesthesia complications mainly applies to people who have Venezuelan lineage through their mother’s side of the family.

You may be at risk if:

• Your mother is of Venezuelan lineage
• Your maternal grandmother is of Venezuelan lineage
• You have other Venezuelan lineage on your mother’s side
• A blood relative on your mother’s side had a serious or unexplained complication after anesthesia

Your risk relates to your genetic lineage, not to Venezuelan nationality. It is not about citizenship, identity, or where you were born. A person may be born in the United States or another country and still have maternal Venezuelan lineage.

The questions from your care team are meant to plan safe care for you or your child. Share what you know. If you do not know all the details, that is okay.

Are children with Venezuelan lineage affected?

The reports have included both children and adults. Right now, doctors do not know enough to say that children with Venezuelan lineage are affected differently from adults.

If your child needs surgery or a procedure with anesthesia, tell your anesthesiologist if the child has Venezuelan lineage on their mother’s side. This applies even if your child or their maternal relative was born outside of Venezuela.

What problems have been reported in these cases?

In the cases being studied, some patients had serious brain and nervous system problems after general anesthesia, including brain injury, stroke-like symptoms, seizures, and taking a long time to wake up. Some patients died.

These outcomes are very rare, and most people who get general anesthesia, including most people of Venezuelan lineage, do not have these kinds of complications.

Is the effect of the ND4 mutation the same as malignant hyperthermia?

No. The complications associated with the ND4 mutation differ from those of malignant hyperthermia. Malignant hyperthermia is another rare reaction to certain anesthesia medicines that is related to one’s genetic makeup.

Even though these reactions are different, any serious reaction to anesthesia in you or your family is important. Tell your anesthesiologist if you or anyone on your mother’s side of the family has had malignant hyperthermia, very high fever, severe muscle stiffness, trouble breathing, a delay in waking up from anesthesia, seizures, brain symptoms, or death after anesthesia.

What should I tell or ask my anesthesiologist if I have Venezuelan lineage?

Before any surgery or procedure with anesthesia, talk with your anesthesiologist about your family background, anesthesia history, and options.

Tell your anesthesiologist if you have:

• A mother, maternal grandmother, or other maternal relative from Venezuela or with Venezuelan lineage
• A personal history of unusual problems after anesthesia
• A family member who:
  • Had brain injury, stroke-like symptoms, seizures, or serious nerve or brain problems after anesthesia or surgery
  • Took a long time to wake up from anesthesia
  • Experienced confusion after anesthesia, which did not get better as expected
  • Had another serious or unexplained problem after anesthesia
  • Died after surgery or anesthesia

Share what you know. If you are not sure about your family medical history or lineage, say so. Even partial information may help your care team plan safer anesthesia for you.

If you or your child may be at risk, you may also want to ask:

• “Does my (or my child’s) maternal Venezuelan lineage affect the anesthesia plan?”
• “Should I consider genetic testing?”
• “Are there anesthesia options that may lower the risk?”
• “Can inhaled anesthesia gases be avoided?”
• “Would IV anesthesia or regional anesthesia be an option?”
• “Will I (or my child) need special monitoring?”
• “What symptoms should my family or I watch for after surgery?”
• “How will you manage this risk?”

If surgery is not urgent, the anesthesiologist may have time to review your family history. They may also talk about genetic testing or other anesthesia options. If surgery is urgent, the team will make the safest plan they can with the information they have.

What if there is no family history of anesthesia problems?

You should still tell your anesthesiologist if your mother, maternal grandmother, or another close relative on your mother’s side is from Venezuela.

While a family history of problems with anesthesia is important, the absence of a known family history of such problems does not rule out risk. Some relatives may never have had surgery, some details may not be known, and some past problems may not have been linked to anesthesia at the time.

Can surgery still be done safely if I’m of Venezuelan lineage?

In many cases, yes. Having Venezuelan lineage or a possible risk for the ND4 gene mutation does not mean you cannot have surgery or anesthesia.

It does mean your anesthesiologist may need to look more closely at your family history. To ensure your safety during or after surgery or your procedure, they may consider testing, talk with your surgical team, adjust your anesthesia plan, and watch you closely during and after surgery.

If surgery is urgent or an emergency, waiting may be more dangerous than the potential risks of anesthesia. Your anesthesiologist will weigh the risks and develop the safest possible plan.

What anesthesia options may lower my risk if I’m of Venezuelan lineage?

If your anesthesiologist thinks you may be at risk, they may change your anesthesia plan. This may include avoiding certain inhaled anesthesia gases.

One option may be total intravenous anesthesia, or TIVA. With TIVA, anesthesia medicines are given through an IV, not via inhaled anesthesia gases. Your anesthesiologist may also use special monitoring during surgery.

For some procedures, regional anesthesia may be an option. This includes a nerve block, spinal anesthesia, or local numbing medicine.

The best plan depends on your health, the type of surgery, your family history, and the urgency of the surgery.

Should I get genetic testing if I’m of Venezuelan lineage?

Genetic testing is an option if you have direct maternal Venezuelan lineage. It may be most helpful before a scheduled surgery or a procedure that is not urgent. However, whether you should get tested depends on your family history, the type of surgery, how urgent the surgery is, and whether the testing can be completed in time.

Keep in mind: At this time, there is no quick test that can be done right before surgery to check for the mutation. But do not cancel or delay surgery on your own. Talk with your surgeon and anesthesiologist about the safest plan for your anesthesia care if you are concerned about this gene mutation.

How can I learn about the latest updates?

ASA is continuing to follow the reports of serious brain and nerve problems after general anesthesia in some patients of Venezuelan lineage. Our understanding of this topic is evolving as doctors learn more. ASA will share updates on its website as more information becomes available.

What should I do next?

If you may have Venezuelan lineage on your mother’s side:

1. Tell your surgeon and anesthesiologist early. Share this information before the day of surgery if possible.
2. Ask your family about relatives’ anesthesia history. Find out if relatives, especially on your mother’s side, had serious problems after anesthesia.
3. Share everything you know. If you know where in Venezuela your mother’s family is from, tell your anesthesiologist.
4. Ask about genetic testing. Testing may help identify this condition in some cases. Explore this option before your surgery, especially if the surgery is not urgent.
5. Gather records if you can. Records from a past anesthesia problem may help your Anesthesia Care Team plan for your next procedure.
6. Watch for serious symptoms after surgery. If you or your child has seizures, stroke-like symptoms, confusion that does not improve, trouble waking up, or other serious brain or nerve symptoms after surgery—especially after leaving the hospital or surgery center—seek emergency care right away.
7. Do not delay urgent care without medical advice. Your anesthesiologist will make the safest plan possible.
8. Plan for emergencies. If you need emergency surgery, do not delay care. Instead, be prepared:
   • Tell the care team right away if you have Venezuelan lineage on your mother’s side of the family.
   • Make sure your family knows about your lineage and the related risk. That way, if you cannot speak for yourself, a family member can say: “This patient has maternal Venezuelan lineage and may have a rare anesthesia risk. Please tell the anesthesiologist.”
   • Consider adding this information to your medical record, phone medical ID, wallet note, or medical alert tag.