The IDH3A gene helps your cells turn food into usable energy. This gene plays an important role in energy production inside mitochondria, the parts of cells often called their power centers. If the IDH3A gene does not work properly, energy-hungry tissues such as the retina may be affected. Some people with pathogenic variants in both copies of this gene develop an inherited retinal condition, often with night blindness and gradually reduced side vision.
What is a gene?
Genes are stretches of DNA that carry instructions your cells use to make molecules or to regulate activities in the body. Some genes provide the directions for building proteins, which are the parts of cells that do much of the work. Others mainly help manage when certain processes happen, where they happen, and how active they are. Taken together, genes affect how the body grows and works, and they can influence how you react to food, stress, or medications. For a more detailed look at this topic, you can find more in the LearnHub.
Overview
IDH3AGene function
What if the gene works
The IDH3A gene helps mitochondria turn food into energy. Its protein carries out a key step in the cell’s energy cycle, helping cells make the fuel they need for normal function.
Risk
What if the gene does not work
When the IDH3A gene does not work properly, it most often affects the retina and can lead to inherited vision loss, including retinitis pigmentosa. Milder and more severe variants can influence when symptoms begin and how much sight is affected.
Treatment
What does that mean for your treatment
No treatment or management approach tailored to pathogenic variants in the IDH3A gene is currently established in clinical guidelines. Research is exploring inherited retinal disease therapies, including gene based approaches, for people with IDH3A variants, but these remain investigational.
Conditions associated with IDH3A
Gene function
What if the gene works
The IDH3A gene helps your mitochondria, the parts of cells that make energy, carry out a key step in turning food into usable fuel. Its protein is part of a small enzyme team that keeps the cell’s main energy cycle moving. Understanding how the IDH3A gene works helps explain how cells make steady energy from nutrients every day.
The IDH3A gene helps run the citric acid cycle, a central pathway cells use to release energy from food. This keeps energy production moving in a controlled, stepwise way inside mitochondria.
Its protein helps change isocitrate into α-ketoglutarate, which is one of the routine chemical steps cells use during energy production. That conversion also prepares the cell for the next steps in the pathway.
This step makes NADH, a molecule that carries energy to the cell’s power-making system. In this way, the IDH3A gene supports the steady production of ATP, the cell’s main usable energy source.
What is a variant?
A genetic variant is a slight difference in a gene’s DNA sequence. These differences are common and help shape normal human diversity, including variations in appearance, metabolism, and the way the body reacts to environmental influences. Many do not have any noticeable effect and are simply part of natural genetic variation. Sometimes, though, a variant changes how a gene works more significantly and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Changes in the IDH3A gene can alter the protein's shape or stability, weaken how it joins its enzyme partners, and reduce a key step in energy production in mitochondria, the parts of cells that make energy. This is how IDH3A gene variants affect cell energy production. Some variants leave partial activity, while more disruptive variants can cause little or no function; in IDH3A-related retinal disease, greater loss of function often goes with earlier and more marked vision problems.
How variants are linked to conditions
Pathogenic variants in the IDH3A gene are best established as a cause of rare inherited retinitis pigmentosa, an eye condition that gradually affects night vision and side vision. In this setting, the clearest evidence involves two disease causing variants, one inherited from each parent. Some reports also describe broader eye findings in a few families, but the main confirmed IDH3A gene variants linked to retinitis pigmentosa involve this inherited retinal condition.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of human biology and are widely seen in the general population. Most do not have a direct effect on health and simply reflect normal human diversity. For many genes, carrying a variant associated with a condition indicates a possible link rather than a definite diagnosis, especially when several genes and environmental factors also contribute. In some situations, though, a single well characterized variant in a particular gene can be 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 health risk related to the IDH3A gene. In families with an inherited IDH3A-related condition, risk is shaped mainly by the exact gene change and whether one or both copies are affected, and a doctor or genetic counselor can help explain personal risk.
Inheritance of IDH3A variants
IDH3A-related conditions are inherited in an autosomal recessive pattern. This means a person usually inherits one IDH3A variant from each parent, and both parents are often healthy carriers. When both parents carry an IDH3A 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 variant. In practical terms, IDH3A inheritance follows the pattern seen with many recessive retinal conditions, where the condition can appear in a child even when there is no previous family history.
What does my IDH3A result mean for my family?
For IDH3A, the best-established family pattern is recessive, which means close relatives may also be carriers even if they do not have symptoms. Brothers and sisters of an affected family member may have the same condition or may be carriers, and other blood relatives may also carry the variant. This can matter for family planning and for relatives who want to better understand their own genetic risk.
Genetic information
Genetic testing
How you find out about variants
IDH3A genetic testing looks for variants in the IDH3A gene using a blood sample, saliva sample, or cheek swab. A lab reads the DNA code to see whether a change is present, and results are usually reported as a variant linked to disease, a harmless variant, or a change with unclear meaning.
When should I consider getting a genetic test?
Consider IDH3A testing when there is unexplained inherited vision loss, especially night blindness, narrowing side vision, or a diagnosis such as retinitis pigmentosa. It can also help when several relatives have similar eye problems or when a child has early, progressive retinal disease.
A genetic result is only one part of your health story
Genetic test results can be very informative, but what they can tell you varies with the condition and the specific kind of variant. Over time, the way your body functions is also shaped by factors like lifestyle, environment, age, and medical history. In some conditions, particularly those affected by many genes, genetic information offers context rather than certainty and makes the most sense when considered with the rest of a person’s care. In other situations, a genetic finding can give a clear answer. For topics such as response to medications, genetic results can also help put personal experiences in 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 medication may work well for one person but less well for another, or why some people are more likely to notice side effects. These differences are common and are one part of the bigger picture, along with age, other health conditions, and other medicines.
What is Pharmacogenetics?
Pharmacogenetics is the study of how differences in genes can affect the way people respond to medications. It examines gene and drug patterns to help explain why the same treatment may work differently from one person to another. For many medicines, genes influence either how strongly a drug works or how the body handles it. This information can support treatment decisions that are more informed and more personalized. More detail on this topic is available in the LearnHub.
Drugs influenced by the IDH3A 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, so any concerns about side effects, new symptoms, or medication changes are best discussed with your doctor.