The NDUFS3 gene helps your cells make energy inside mitochondria, your cells’ energy centers. If this gene does not work properly, cells may struggle to meet energy needs, especially in the brain, muscles, and heart. This gene plays an important role in one of the main energy systems in mitochondria, so disease-causing variants can lead to a mitochondrial condition with symptoms such as low muscle tone, movement problems, seizures, or developmental delay. NDUFS3 is mainly discussed in medical genetics rather than in popular culture.
What is a gene?
Genes are sections of DNA that give cells instructions for making molecules or managing processes in the body. Some genes carry the code for producing proteins, which are the active parts of cells. Others mostly guide when certain processes happen, where they take place, and how strong their activity is. Taken together, genes affect how the body grows and works, and they can influence how you respond to food, stress, and medications. For a more detailed look at this subject, you can read more in the LearnHub.
Overview
NDUFS3Gene function
What if the gene works
The NDUFS3 gene helps build complex I, a key part of mitochondria, the structures that power cells. This supports a steady energy supply, especially in the brain, muscles, and other active tissues.
Risk
What if the gene does not work
Variants in the NDUFS3 gene can reduce how well cells make energy, causing mitochondrial disease in some people. More severe variants may cause earlier, more obvious brain, muscle, or heart problems, while milder variants can lead to later, variable symptoms.
Treatment
What does that mean for your treatment
No treatment or drug choice approach specific to the NDUFS3 gene is currently established. Research is exploring ways to support mitochondrial complex I function and gene based treatments for conditions linked to the NDUFS3 gene, but these remain investigational.
Conditions associated with NDUFS3
Gene function
What if the gene works
Your cells need the NDUFS3 gene to help mitochondria turn food into usable energy. Inside these energy centers, its protein supports complex I, the first major step in the cell’s energy chain. This is central to the NDUFS3 gene’s role in mitochondrial energy production and the steady supply of ATP, the cell’s main fuel.
The NDUFS3 gene provides a key piece of complex I, which begins the process of extracting energy from nutrients. This early step helps your cells keep a steady flow of ATP, the fuel they use for everyday work.
As part of complex I, the NDUFS3 protein supports the movement of electrons, tiny charged particles, through the mitochondrial energy chain. This helps mitochondria build up energy across their inner membrane, which they later use to make ATP.
Your cells also use NDUFS3 to help build and stabilize complex I inside mitochondria. When this structure is put together properly, energy production can run in an organized, efficient way.
What is a variant?
A genetic variant is a small difference in the DNA sequence of a gene. These differences are common and help create normal human diversity, such as variation in appearance, metabolism, or how the body responds to environmental influences. Many have no noticeable effect and are simply part of natural genetic variation. In some cases, 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 NDUFS3 gene can weaken a core part of mitochondrial complex I, so this energy-making machinery is assembled poorly or works less well. How NDUFS3 gene variants affect mitochondrial function depends on the change: milder variants may leave some activity, while more severe variants can greatly reduce complex I assembly or stop it. This lowers cellular energy production and, in established disease caused by variants in the NDUFS3 gene, can be linked to earlier or more marked symptoms.
How variants are linked to conditions
Pathogenic variants in the NDUFS3 gene cause a rare mitochondrial condition called complex I deficiency, often diagnosed as Leigh syndrome or a Leigh-like condition. In people with NDUFS3-related mitochondrial disease, health effects usually begin in infancy or childhood, though the severity can vary. The clearest established finding is that NDUFS3 gene variants linked to Leigh syndrome are part of this broader NDUFS3-related complex I deficiency diagnosis.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are widely seen in the general population. Most do not have a direct effect on health and instead represent natural human diversity. For many genes, carrying a variant associated with a condition indicates a possible link rather than a definite diagnosis, particularly when several genes and environmental factors contribute. In some situations, though, one well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For NDUFS3, risk is mainly shaped by whether someone has disease-causing changes in both copies of the gene, rather than by lifestyle or common outside factors. There is not broadly confirmed evidence that diet, exercise, or other everyday factors can meaningfully change the chance of developing an NDUFS3-related condition, though avoiding major illness stress may help limit complications in people already affected.
Inheritance of NDUFS3 variants
NDUFS3-related conditions are inherited in an autosomal recessive pattern. This means a person usually develops the condition only if they inherit two altered copies of the NDUFS3 gene, one from each parent. Parents who each carry one variant are usually unaffected carriers, and with each pregnancy they have a 25% chance of having an affected child, a 50% chance of having a carrier child, and a 25% chance of having a child without the familial variants. In practical terms, the NDUFS3 inheritance pattern often appears in families with no prior history because carrier parents may not know they carry a variant.
What does my NDUFS3 result mean for my family?
For families with an NDUFS3-related condition, close relatives may also carry the same gene change, even if they do not have symptoms. Brothers and sisters may be affected or may be healthy carriers, and parents are usually carriers. Other relatives, such as aunts, uncles, and cousins, may also carry the change, so the result can matter beyond one person.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for variants in the NDUFS3 gene usually uses a blood sample, saliva, or a cheek swab. A lab reads the DNA code in the NDUFS3 gene, often in a larger test that checks many genes linked to mitochondrial conditions, to see whether a variant is present.
When should I consider getting a genetic test?
Genetic testing for the NDUFS3 gene may be worth considering when a child or adult has signs of a mitochondrial condition, such as developmental delay, muscle weakness, seizures, movement problems, or repeated high lactic acid levels. It can also help when there is a family history of Leigh syndrome or a similar inherited energy condition.
A genetic result is only one part of your health story
Genetic results can offer useful insight, but how much they reveal varies by the condition and the type of variant involved. Over time, many factors, including lifestyle, environment, age, and medical history, also shape how the body works. For some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is best understood together with other parts of care. In other situations, a genetic result can give a clear answer. In areas such as medication response, these results can also help put individual experiences into perspective.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Some people break down a drug more slowly or more quickly, while others may be more or less sensitive to its effects. This helps explain why the same medication can work well for one person, have less benefit for another, or cause more side effects in someone else.
What is Pharmacogenetics?
Pharmacogenetics looks at how genetic differences affect the way a person responds to medication. It examines relationships between genes and drugs to help explain why the same treatment may work differently from one person to another. For many medicines, genes can influence how strongly a drug works or how the body processes it. This information can help support more informed, individualized treatment decisions. To explore this subject in greater detail, you can learn more in the LearnHub.
Drugs influenced by the NDUFS3 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in predicting medication response, so concerns about side effects, worsening symptoms, or whether a treatment is right for you are best discussed with your doctor.