The NDUFA3 gene helps your mitochondria, the parts of cells that make energy, build and run complex I, an early step in turning food into usable energy. If this gene does not work properly, cells may struggle to make enough energy, especially in the brain, muscles, and heart. A severe variant can cause a mitochondrial condition called complex I deficiency, which may lead to poor growth, low muscle tone, developmental delay, seizures, or heart problems. Most people only hear about this gene during genetic testing for unexplained symptoms.
What is a gene?
Genes are stretches of DNA that give your cells instructions to make molecules or manage processes in the body. Some carry the information needed to build proteins, which are the parts of cells that do much of the work. Others mostly help regulate when, where, and how strongly certain processes happen. Taken together, genes affect how the body grows and works, and they can influence how you respond to food, stress, and medications. You can learn more about this topic in the LearnHub.
Overview
NDUFA3Gene function
What if the gene works
The NDUFA3 gene helps cells make energy by supporting a key step in the mitochondria, the parts of cells that turn food into fuel. This is especially important in the brain, muscles, and heart.
Risk
What if the gene does not work
More severe variants in the NDUFA3 gene can impair mitochondrial energy production and cause mitochondrial disease, often with symptoms affecting the brain, low muscle tone, and high lactate; milder variants may cause later onset or a less severe course.
Treatment
What does that mean for your treatment
For the NDUFA3 gene, no established NDUFA3-specific treatment or drug-selection approach is currently part of clinical guidelines; care is guided by the person’s symptoms rather than by the exact variant.
Gene function
What if the gene works
Your cells need a steady energy supply for movement, growth, and routine organ function. The NDUFA3 gene helps mitochondria, the parts of cells that make most of your body’s energy, carry out an early step in mitochondrial energy production. When it works normally, cells can turn nutrients into usable energy more smoothly.
The NDUFA3 gene helps build and run complex I, an early part of the cell’s energy chain inside mitochondria. This supports the process that converts energy from food into ATP, the cell’s main fuel.
This gene makes a small protein that becomes part of complex I in the inner mitochondrial membrane. Its presence helps the larger complex form properly and stay organized during normal cell activity.
NDUFA3 supports the step where electrons move through complex I as cells extract energy from nutrients. This helps keep the wider energy making system moving in a coordinated way.
What is a variant?
A genetic variant is a small change in the DNA sequence of a gene. These changes are common and are part of normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many variants have no noticeable effect and simply represent natural genetic variation. In some cases, though, a variant can change how a gene functions more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
How NDUFA3 gene variants affect energy production depends on the change. Some variants make the small protein from the NDUFA3 gene unstable or misshapen, so complex I in mitochondria (the parts of cells that make energy) cannot assemble or work well. Milder variants may leave some activity, while more disruptive variants can sharply reduce complex I function or stop its assembly. This range can influence how early mitochondrial disease appears and how severe it becomes.
How variants are linked to conditions
Disease-causing variants in the NDUFA3 gene can cause a rare mitochondrial condition called complex I deficiency. In published cases, NDUFA3 gene variants and mitochondrial disease have been linked to early-onset illness, often with developmental delay, low muscle tone, seizures, and lactic acidosis. When disease-causing variants are present in both copies of the gene, they can confirm an NDUFA3-related diagnosis.
A variant is not necessarily a diagnosis
Variants in genes are a normal part of human biology and are widely found in the general population. Most do not have a direct effect on health and simply reflect 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 also play a role. In other cases, one well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
There is not yet broadly confirmed evidence on specific factors that increase or reduce risk related to the NDUFA3 gene. For families with a known NDUFA3 change, personal risk is mostly shaped by the inherited variant, and a doctor or genetic counselor can help explain what that means.
Inheritance of NDUFA3 variants
NDUFA3-related conditions are inherited in an autosomal recessive pattern. This means a child usually needs to inherit one altered copy of the NDUFA3 gene from each parent to be affected, while parents with one altered copy are typically carriers. When both parents carry an NDUFA3 gene variant, each pregnancy has a 25% chance of the child inheriting both altered copies, a 50% chance of being a carrier, and a 25% chance of inheriting neither altered copy. In families asking how NDUFA3 gene variants are inherited, this two-parent carrier pattern is the key point.
What does my NDUFA3 result mean for my family?
For families, an NDUFA3-related condition is usually inherited in a recessive way, which means parents are often healthy carriers and siblings may also carry the same gene change. Brothers and sisters can sometimes be affected or be carriers, even if no one else in the family has symptoms. More distant relatives may also carry the change, especially on the side of the family it came from.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a variant in the NDUFA3 gene, a lab can analyze DNA from a blood sample or cheek swab using genetic testing for NDUFA3 variants. The lab reads the gene’s sequence and compares it with the usual pattern to identify variants that may help explain symptoms or clarify an inherited condition.
When should I consider getting a genetic test?
Testing for changes in the NDUFA3 gene may be considered when a baby or child has signs of a condition that affects the body’s energy supply, such as severe early developmental problems, low muscle tone, feeding trouble, seizures, or high lactic acid levels. It can also help when a close relative has a confirmed NDUFA3-related condition.
A genetic result is only one part of your health story
A genetic result can provide useful information, but how much it reveals depends on the condition and on the type of variant involved. Many factors, including lifestyle, environment, age, and medical history, influence how the body functions over time. For some conditions, especially those shaped by many genes, genetic information provides context rather than certainty and is best viewed alongside other parts of care. In other situations, a genetic result may offer a clear answer. In areas such as medication response, genetic 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. A treatment that works well for one person might work less well for another, or it may cause more side effects, because the body can absorb, break down, transport, or respond to a drug in different ways. These differences are common and are one reason medication response is not always the same from person to person.
What is Pharmacogenetics?
Pharmacogenetics examines the ways genetic differences can affect how people respond to medicines. By studying links between genes and medications, it helps explain why the same treatment may work differently in different people. For many drugs, a person’s genes can influence both how strongly the medicine acts and how the body handles it. Understanding this can support treatment choices that are more informed and more individualized. More detailed information on this topic is available in the LearnHub.
Drugs influenced by the NDUFA3 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding how medicines are chosen or used. Questions about side effects, new symptoms, or how well a treatment is working are best discussed with your doctor.