The TARS2 gene helps mitochondria, the parts of cells that make energy, produce the proteins they need to work properly. This gene helps your body keep energy production running, especially in tissues like the brain and muscles. If both copies do not work well because of pathogenic variants, a person can develop a mitochondrial condition with developmental delay, seizures, hearing loss, movement problems, or weakness, often beginning early in life.
What is a gene?
Genes are pieces of DNA that give your cells instructions to make molecules or manage processes in the body. Some genes hold the information needed to produce proteins, the parts of cells that do much of the work. Other genes mainly regulate when certain processes take place, where they happen, and how strongly they run. Together, genes influence how the body develops and functions, and they can affect how you respond to food, stress, or medications. To explore this topic in more detail, you can learn more in the LearnHub.
Overview
TARS2Gene function
What if the gene works
The TARS2 gene helps mitochondria, the parts of cells that make energy, build some of their own proteins. This supports normal energy production, especially in the brain, muscles, and other tissues with high energy needs.
Risk
What if the gene does not work
Harmful variants in the TARS2 gene can cause a mitochondrial condition linked to developmental delay, seizures, and hearing loss. Milder and more severe variants can affect which features appear and how early they start.
Treatment
What does that mean for your treatment
No TARS2-specific treatment or drug selection approach is currently established for people with a pathogenic or loss-of-function variant in the TARS2 gene.
Conditions associated with TARS2
Gene function
What if the gene works
Your cells use the TARS2 gene to help mitochondria make some of their own proteins. Mitochondria are the parts of cells that turn food into usable energy. When this gene is working normally, it helps keep that protein-making process accurate and steady.
The TARS2 gene helps place the amino acid threonine onto the correct mitochondrial transfer RNA, a small helper used to build proteins. This matching step helps your cells use the right building block at the right time.
Inside mitochondria, TARS2 supports mitochondrial protein production by preparing one of the key ingredients needed for assembly. This helps mitochondria make several proteins they need for routine cell work.
By helping mitochondria build their own proteins, the TARS2 gene supports the cell processes that make energy. This is especially important in tissues that need a steady energy supply, such as muscles and the brain.
What is a variant?
A genetic variant is a small difference in the DNA sequence within a gene. These changes are common and help make up normal human diversity, such as differences in appearance, metabolism, or how the body responds to environmental influences. Many variants do not cause any noticeable effect and simply represent natural genetic variation. In some situations, though, a variant can affect how a gene works more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the TARS2 gene can alter the shape, stability, or activity of a mitochondrial enzyme, which helps explain how TARS2 gene variants affect mitochondrial protein production. Many reduce how well the enzyme attaches threonine to mitochondrial transfer RNA, so the cell makes fewer energy-making proteins. Some variants leave partial activity, while more severe variants can disrupt this step much more strongly. In TARS2-related mitochondrial disease, lower remaining activity often goes with earlier onset and more pronounced features.
How variants are linked to conditions
Pathogenic variants in the TARS2 gene cause a rare mitochondrial condition called combined oxidative phosphorylation deficiency 21. This condition linked to TARS2 gene variants usually begins in infancy or childhood and may include developmental delay, low muscle tone, seizures, hearing loss, or movement and balance problems. A confirmed pathogenic TARS2 variant can establish the diagnosis.
A variant is not necessarily a diagnosis
Variants in genes are a usual part of human biology and are widespread in the general population. Most have no direct effect on health and simply reflect natural 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 play a role. In some cases, 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 TARS2-related disease, risk is mostly determined by whether a child inherits harmful TARS2 changes from both parents. A family history of the condition, known carrier parents, or parents who are related by blood can raise the chance, while lifestyle does not meaningfully change this genetic risk.
Inheritance of TARS2 variants
TARS2-related conditions are inherited in an autosomal recessive pattern. This means a person usually develops the condition only if they inherit two disease-causing variants in the TARS2 gene, one from each parent. Parents who each carry one variant are typically unaffected carriers, and with each pregnancy they have a 25% chance of having an affected child. In practical terms, how TARS2 gene variants are inherited means brothers and sisters can be affected, while the variant can pass quietly through a family for generations.
What does my TARS2 result mean for my family?
For families with a disease-causing TARS2 result, the pattern is usually recessive, which means parents are often healthy carriers and brothers or sisters may also have the condition or be carriers. Other close relatives, such as aunts, uncles, and cousins on both sides, may also carry the same gene change. Family testing can help clarify who else may be affected or carry it.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for TARS2 variants is usually done on a blood sample, saliva, or cheek swab. A lab reads the DNA sequence of the TARS2 gene and checks for changes that may help explain symptoms or confirm a genetic diagnosis. Results may show a pathogenic variant, a benign variant, or a variant of uncertain significance.
When should I consider getting a genetic test?
Testing for the TARS2 gene may be considered when a child has signs of a rare inherited mitochondrial condition, such as early developmental delay, low muscle tone, seizures, or unexplained high lactic acid levels, especially if similar problems run in the family. It can also help clarify the cause when other tests have not explained these symptoms.
A genetic result is only one part of your health story
Genetic testing can provide useful insight, but how much it reveals depends on the condition and the kind of variant involved. Over time, many factors, including lifestyle, environment, age, and medical history, influence how the body functions. For some conditions, especially those shaped by many genes, genetic information offers context rather than certainty and is most helpful when viewed alongside other parts of care. In other situations, a genetic result can give a clear answer. In areas such as response to medications, these results can help put individual experiences into context.
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 may work less well for another, or may cause more side effects, because the body can absorb, break down, transport, or respond to a drug differently. These differences are common and can influence how strongly a medicine works or how sensitive someone is to it.
What is Pharmacogenetics?
Pharmacogenetics is the area of study that looks at how genetic differences affect a person’s response to medications. It examines connections 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 handles it. This information can help support treatment decisions that are more informed and more individualized. More detail on this topic is available in the LearnHub.
Drugs influenced by the TARS2 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in predicting how medicines will work, so any concerns about side effects, medication changes, or new symptoms are best discussed with your doctor.
History
In recent decades, awareness of this gene’s role has grown. The TARS2 gene was identified as part of a wave of research that mapped the genes needed for energy production inside mitochondria, the cell’s energy making structures. It drew more medical attention when researchers connected variants in the TARS2 gene with an inherited mitochondrial condition affecting brain development and muscle tone. That link helped place TARS2 among a broader group of genes involved in mitochondrial disease. From these first observations, research expanded steadily. Today, the TARS2 gene is mainly recognized in genetics and rare disease medicine rather than in public discussions.