The TEFM gene helps mitochondria, the parts of cells that make energy, read their own DNA correctly so your body can keep making key energy-related proteins. This gene plays an important role in steady energy production, especially in the brain, muscles, and other tissues with high energy needs. If the TEFM gene does not work properly, energy levels in cells can fall and cause an inherited mitochondrial condition. People with harmful variants in the TEFM gene may have developmental delay, low muscle tone, movement problems, seizures, or trouble growing.
What is a gene?
A gene is a stretch of DNA that holds information cells use to make molecules or regulate processes in the body. Some genes carry instructions for producing proteins, the parts of cells that do the work. Others mainly direct when certain processes happen, where they happen, and how active they are. Together, genes affect how the body develops and works, and they can influence how you respond to food, stress, or medications. For a deeper look at this topic, you can read more in the LearnHub.
Overview
TEFMGene function
What if the gene works
The TEFM gene helps mitochondria copy their own genetic instructions into RNA. This supports the production of proteins needed for energy generation in cells, especially in tissues with high energy needs.
Risk
What if the gene does not work
Variants that reduce how well the TEFM gene works can cause a mitochondrial energy condition, often affecting the liver, brain, and muscles. Milder to more severe variants can influence how early problems appear and how strongly a person is affected.
Treatment
What does that mean for your treatment
No TEFM-specific treatment or drug choice approach is currently established for people with a pathogenic variant in the TEFM gene. Care is based on the person’s symptoms and may include supportive management, while TEFM is mainly being studied to better understand mitochondrial disease rather than guide current medicines.
Gene function
What if the gene works
Inside your cells, the TEFM gene supports the steady work of mitochondria, the parts of cells that make most of your usable energy. Understanding how the TEFM gene works in mitochondria helps show how cells keep up with daily energy needs. It does this by helping mitochondria read their own DNA and make the RNA messages they need.
The TEFM gene helps mitochondria read their own DNA into RNA messages, which are working copies of genetic instructions. This keeps essential mitochondrial genes available for normal cell activity.
Its protein helps the mitochondrial copying process keep going instead of stopping too early. This allows full length RNA messages to be completed for routine mitochondrial tasks.
These RNA messages are used to make key parts of the energy making system inside mitochondria. By supporting that step, the TEFM gene helps cells meet everyday energy demands.
What is a variant?
A genetic variant is a minor difference in the DNA sequence of a gene. These differences are common and help shape normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many variants do not have any noticeable effect and simply reflect natural genetic variation. In some cases, though, a variant can change 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 TEFM gene can make the TEFM protein less stable or less able to support mitochondrial transcription, where mitochondria create RNA instructions from mitochondrial DNA. This is how variants in the TEFM gene can affect mitochondrial function, because some proteins needed for energy production are made in lower amounts. Milder variants may leave some activity in place, while more severe variants can cause a drop in function and are often linked to earlier or more pronounced mitochondrial disease.
How variants are linked to conditions
Pathogenic variants in the TEFM gene cause a rare mitochondrial disease called combined oxidative phosphorylation deficiency 35. In practice, TEFM gene variants are linked to severe early childhood illness that may include developmental delay, low muscle tone, seizures, breathing problems, and liver disease, including liver failure in some children. When a disease-causing TEFM variant is found in the right clinical setting, it can confirm the genetic diagnosis.
A variant is not necessarily a diagnosis
Genetic variants are common across the general population and are a normal feature of human biology. Most do not directly affect health and simply reflect natural human diversity. For many genes, having a variant linked to a condition points to a possible association rather than a definite diagnosis, especially when multiple genes and environmental factors play a role. In some situations, though, one well characterized variant in a particular 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 health risk related to the TEFM gene. For many living with TEFM-related changes, risk depends mainly on the exact genetic change and whether one or two copies are affected, rather than on lifestyle or environmental factors.
Inheritance of TEFM variants
TEFM-related conditions are inherited in an autosomal recessive pattern. In practical terms, how TEFM gene variants are inherited usually means a child needs to receive one changed copy of the TEFM gene from each parent to be affected. Parents who each carry one variant are often unaffected themselves, and with each pregnancy there is 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 two usual copies of the gene. This pattern affects sons and daughters equally.
What does my TEFM result mean for my family?
For TEFM-related disease, the family pattern is usually recessive, which means parents are often healthy carriers. Brothers and sisters may also be affected or may be carriers, and other close relatives could be carriers too. This kind of result can matter for family planning and for relatives who want to understand their own chances of having an affected child.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for TEFM variants usually uses a blood or saliva sample. A lab reads the TEFM gene as part of a targeted panel, exome, or genome test to look for DNA changes that may help confirm a diagnosis or clarify whether the TEFM gene is involved.
When should I consider getting a genetic test?
Testing for the TEFM gene may be considered when a baby or child has signs of a rare inherited energy-production condition, such as severe muscle weakness, developmental delay, feeding problems, seizures, or repeated liver trouble. It can also help if there is a family history of this kind of mitochondrial condition.
A genetic result is only one part of your health story
A genetic result can provide valuable 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, shape how the body functions. 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 may offer a clear answer. In areas like medication response, genetic results can also help put individual experiences in context.
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, so the same dose can have a different effect from one person to another. This can influence how well a treatment works or how likely someone is to notice side effects, and it is a common reason medication response varies between people.
What is Pharmacogenetics?
Pharmacogenetics examines how differences in a person’s genes affect the way they respond to medicines. By studying links between genes and medications, it helps explain why the same treatment can work differently in different people. For many drugs, genes can influence how the body handles a medicine or how strong its effects are. This information can support treatment choices that are more individualized and better informed. More detailed information on this topic is available in the LearnHub.
Drugs influenced by the TEFM 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 whether side effects are more likely. For any concerns about symptoms, new treatments, or medication changes, it is best to speak with your doctor or pharmacist.