The ETHE1 gene helps your body break down sulfur containing substances so cells, especially in energy hungry tissues, can work safely. This gene plays an important role in the mitochondria, the parts of cells that make energy. If the gene does not work well, toxic sulfur byproducts can build up and harm the brain, blood vessels, intestines, and muscles. Pathogenic variants in the ETHE1 gene cause ethylmalonic encephalopathy, a rare inherited condition that often begins in infancy with developmental delay, weak muscle tone, diarrhea, and other neurologic problems.
What is a gene?
Genes are sections of DNA that carry instructions your cells use to make molecules or regulate processes in the body. Some genes hold the information needed to produce proteins, the working parts of cells. Others mainly direct when certain processes happen, where they take place, and how strongly they run. In combination, genes influence the body’s development and function, and they can shape how you respond to food, stress, or medications. For a more detailed look at this topic, you can visit the LearnHub.
Overview
ETHE1Gene function
What if the gene works
The ETHE1 gene helps cells break down hydrogen sulfide, a gas your body makes in small amounts. This supports normal energy production in mitochondria, the parts of cells that make energy.
Risk
What if the gene does not work
More disruptive variants in the ETHE1 gene can cause ethylmalonic encephalopathy, often beginning in infancy with developmental slowing, weak muscle tone, diarrhea, and blood vessel related skin changes. Milder variants may leave enzyme activity and can affect timing and severity.
Treatment
What does that mean for your treatment
A pathogenic variant in the ETHE1 gene supports treatment aimed at lowering sulfide buildup, most often with metronidazole plus N-acetylcysteine. Some people, especially with more severe illness, may also be considered for liver transplantation as part of management.
Conditions associated with ETHE1
Gene function
What if the gene works
Inside the parts of your cells that make energy, ETHE1 helps process sulfur in a safe, controlled way. It is especially important for breaking down hydrogen sulfide, a sulfur gas made during normal body activity and by bacteria in the gut. Understanding how the ETHE1 gene helps break down hydrogen sulfide makes its role in everyday cell health easier to see.
ETHE1 helps your mitochondria break down hydrogen sulfide, a sulfur gas your body makes during normal metabolism. This keeps sulfide levels in a healthy range so cells can carry out everyday work.
By clearing sulfide, ETHE1 helps protect the energy making machinery inside cells. This supports steady energy production in tissues that need a reliable supply, including the brain, muscles, and digestive tract.
ETHE1 is part of a pathway that changes reactive sulfur compounds into forms the body can handle more easily. This helps maintain normal sulfur balance inside cells and supports routine cell chemistry.
What is a variant?
A genetic variant is a minor difference in a gene’s DNA sequence. These changes are common and help shape normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many have no noticeable effect and simply reflect natural genetic variation. Sometimes, though, a variant changes how a gene functions more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the ETHE1 gene can change the shape or stability of its protein, so cells break down sulfur compounds less effectively in mitochondria (the parts of cells that make energy). This explains how ETHE1 gene variants affect protein function at a cellular level. Milder variants may leave some protein activity, while more severe variants can greatly reduce or nearly abolish it. In ethylmalonic encephalopathy, lower remaining activity often tracks with earlier and more pronounced symptoms.
How variants are linked to conditions
Pathogenic variants in both copies of the ETHE1 gene cause ethylmalonic encephalopathy, a rare inherited condition. ETHE1 gene variants and ethylmalonic encephalopathy are the main well-established clinical link described in human genetics. People with this diagnosis often develop symptoms in infancy or early childhood, which can include developmental problems, seizures, diarrhea, and blood vessel changes such as small purple skin spots.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of human biology and are widely found in the general population. Most do not directly affect health and simply contribute to natural human diversity. For many genes, carrying a variant associated with a condition suggests a possible link rather than a certain diagnosis, especially when several genes and environmental factors are involved. In some situations, though, a single well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For ETHE1, the chance of having the condition is mainly set by genetics: it happens when a child inherits two nonworking copies of the ETHE1 gene, one from each parent. Risk is higher in families with a known ETHE1 change or when parents are blood relatives. Lifestyle changes do not meaningfully lower the chance of inheriting it.
Inheritance of ETHE1 variants
ETHE1-related conditions are inherited in an autosomal recessive pattern. This means a person usually needs to inherit two disease-causing variants in the ETHE1 gene, one from each parent, to be affected. Parents who each carry one ETHE1 variant are typically unaffected carriers, and with each pregnancy they have a 25% chance of having an affected child, a 50% chance of having a child who is a carrier, and a 25% chance of having a child with no familial ETHE1 variant. In families learning how ETHE1 variants are inherited, this pattern means boys and girls are affected equally.
What does my ETHE1 result mean for my family?
For ETHE1, family members can sometimes carry the same gene change without having symptoms. Brothers and sisters of an affected child may also be affected or may be healthy carriers, and close relatives may want to learn whether the variant runs in the family. This can matter for future pregnancies, because two carrier parents can have another affected child together.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for ETHE1 variants usually uses a blood or saliva sample to read the ETHE1 gene and look for changes in both copies. Results can help confirm an ETHE1-related diagnosis in someone with matching symptoms and can show whether family members carry the same variant.
When should I consider getting a genetic test?
Consider ETHE1 genetic testing if a baby or child has signs that fit this rare inherited condition, such as ongoing diarrhea, weak muscle tone, developmental slowing, or unusual bluish skin coloring and tiny skin spots. Testing can also help when there is a family history of the condition or a known change in the ETHE1 gene in the family.
A genetic result is only one part of your health story
Genetic results can provide valuable insight, but how much they explain varies based on the condition and the type of variant involved. Many other factors, including lifestyle, environment, age, and medical history, also influence how the body works over time. In some conditions, especially those shaped by many genes, genetic information provides context rather than certainty and is best considered together with other parts of care. In other situations, a genetic result can offer a clear answer. In areas such as medication response, these results can also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Small differences in genes can change how the body breaks down a drug, moves it through the body, or responds to it at its target. This helps explain why the same treatment works well for one person, has less effect in another, or causes more side effects in someone who is more sensitive to it.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic variation can affect a person’s response to medications. It looks at gene and drug patterns to help explain why the same treatment may work differently from one person to another. For many medicines, genes influence how strongly a drug works or how the body processes it. This information can help support treatment decisions that are better informed and more individualized. If you want to learn more about this topic, you can explore it further in the LearnHub.
Drugs influenced by the ETHE1 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in predicting how medicines will work or which side effects someone may have, so general questions about treatment, medication side effects, or new symptoms are best discussed with your doctor.
History
ETHE1 entered medical genetics through work on a rare inherited condition called ethylmalonic encephalopathy. In 2004, researchers identified changes in the ETHE1 gene as the cause, giving families a clearer explanation for a condition that had previously been defined mainly by symptoms and lab findings. Initially understood only through visible traits, later recognized as tied to a specific gene, the condition became easier to diagnose with genetic testing. From these first observations, research expanded steadily. ETHE1 also helped strengthen understanding of rare metabolic conditions in which toxic substances build up in the body. Over time, descriptions became more precise, and the gene’s place in this condition became firmly established.