The SLC25A20 gene helps move certain fats into the part of the cell that turns them into energy, especially during fasting, illness, or long gaps between meals. If this gene does not work properly, the body may struggle to use long chain fats for fuel and can develop low blood sugar, muscle weakness, liver problems, or changes in heart rhythm. Pathogenic variants in the SLC25A20 gene cause carnitine acylcarnitine translocase deficiency, a rare inherited condition where cells cannot handle fat energy normally. Symptoms often begin in infancy and may appear during everyday stresses such as infection or not eating for several hours.
What is a gene?
A gene is a stretch of DNA that carries instructions your cells use to make molecules or direct processes in the body. Some genes hold the instructions for making proteins, which are the parts of cells that do the work. Other genes mainly regulate when certain processes happen, where they happen, and how active they are. Taken together, genes influence how the body develops and works, and they can affect how you respond to food, stress, or medications. If you want to go deeper into this topic, you can find more in the LearnHub.
Overview
SLC25A20Gene function
What if the gene works
The SLC25A20 gene helps move certain fats into mitochondria, the parts of cells that make energy. This supports energy production, especially during fasting or exercise, when the body relies more on fat for fuel.
Risk
What if the gene does not work
If the SLC25A20 gene does not work well, the body may struggle to use fats for energy during fasting or illness. This can cause low blood sugar and heart, liver, or muscle problems; variant severity can affect onset and features.
Treatment
What does that mean for your treatment
Pathogenic variants in the SLC25A20 gene usually direct treatment toward strict fasting avoidance, rapid glucose during illness, and a diet low in long-chain fat with medium-chain triglycerides. Triheptanoin can be part of treatment for some people with this type of fatty acid oxidation condition.
Conditions associated with SLC25A20
Gene function
What if the gene works
Your cells need a steady way to move certain fats into mitochondria, the parts that make usable energy. The SLC25A20 gene supports this step by making a transport protein in the inner membrane of mitochondria. This transport is central to how the body uses fat for energy during everyday activities, sleep, and time between meals.
Inside mitochondria, the SLC25A20 gene helps move long-chain fats in a form called acylcarnitine (fat linked to carnitine) across the inner membrane. This brings fat based fuel to the place where cells can turn it into usable energy.
Its protein works as a swap system, bringing these fat carriers in while sending free carnitine back out. This recycling step keeps the transport pathway moving smoothly from one round to the next.
By supporting this transport step, the SLC25A20 gene helps the body use fat for energy during sleep, exercise, and time between meals. It supports a normal shift to stored fat when that is the fuel your cells need.
What is a variant?
A genetic variant is a minor change in the DNA sequence within a gene. These changes are common and help shape normal human diversity, including differences in appearance, metabolism, or how the body responds to environmental influences. Many variants do not have any noticeable effect and are simply part of natural genetic variation. In some cases, though, a variant can more substantially change how a gene works and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the SLC25A20 gene can change the shape, stability, or placement of its transporter protein, so less long chain fat reaches mitochondria to be used for energy. Some SLC25A20 gene variants leave partial transport activity, while more disruptive variants may produce little or no working transporter. This functional spectrum is linked to CACT deficiency, and it can influence how early symptoms appear and how severe they may be.
How variants are linked to conditions
Pathogenic variants in the SLC25A20 gene cause carnitine acylcarnitine translocase deficiency, a rare inherited condition. In practice, SLC25A20 gene variants linked to conditions almost always refer to this diagnosis. People usually develop it when they inherit two disease-causing variants, and symptoms often begin in infancy or early childhood, though severity can vary.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of human biology and are widespread across the general population. Most do not directly affect health and are simply part of natural human diversity. For many genes, having a variant connected with a condition indicates a possible association rather than a confirmed diagnosis, particularly when several genes and environmental factors are involved. In some situations, though, a single well-characterized variant in a specific gene can be enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For people with harmful changes in both copies of the SLC25A20 gene, the main risk comes from the gene change itself rather than lifestyle. Serious illness, fasting, long gaps without food, and sometimes heavy exercise or cold exposure can trigger dangerous metabolic crises, so avoiding these triggers and using a care plan can lower the chance of complications.
Inheritance of SLC25A20 variants
SLC25A20-related conditions follow an autosomal recessive inheritance pattern. In practical terms, inheritance of the SLC25A20 gene variants usually means a child is affected only when they inherit one disease-causing variant from each parent. Parents who each carry one variant are typically unaffected carriers, and with each pregnancy there is a 25% chance the child will inherit both variants, a 50% chance the child will be a carrier, and a 25% chance the child will inherit neither variant. Because the SLC25A20 gene is on an autosome, this pattern is the same for boys and girls.
What does my SLC25A20 result mean for my family?
For families, an SLC25A20 result usually matters in a recessive pattern, which means close relatives may also be carriers even if they are healthy. Brothers and sisters of an affected child may also be affected or may carry the family variant. This can be especially important when planning a pregnancy, because relatives who carry the same variant could have children with this condition if their partner is also a carrier.
Genetic information
Genetic testing
How you find out about variants
Testing for variants in the SLC25A20 gene usually uses a blood or saliva sample. In SLC25A20 genetic testing, a laboratory reads the gene’s DNA code to look for changes and compares them with known variant patterns. Results are interpreted alongside a person’s symptoms and family history.
When should I consider getting a genetic test?
Genetic testing for the SLC25A20 gene may be considered if a baby or child has signs of a rare energy-use condition, such as low blood sugar during fasting, heart or liver problems, muscle weakness, or an abnormal newborn screening result. It can also help when this condition runs in the family or a relative carries an SLC25A20 variant.
A genetic result is only one part of your health story
A genetic result can provide useful insight, but how much it explains varies by the condition and the type of variant involved. Many factors, including lifestyle, environment, age, and medical history, shape how the body works over time. In 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 offer a clear answer. In areas like medication response, genetic findings can help place individual experiences in context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body responds to medicines. Small differences in genes can change how a drug is absorbed, broken down, moved through the body, or how strongly it acts on its target. This helps explain why the same medication may work well for one person, seem less effective for another, or cause more side effects in someone else.
What is Pharmacogenetics?
Pharmacogenetics is the study of how genetic differences shape the way people respond to medications. It explores links between genes and drugs to help explain why treatments can work differently from one person to the next. For many medicines, genes affect how strongly a drug works or how the body processes it. This information can help support treatment decisions that are more individualized and better informed. You can read more about this topic in the LearnHub.
Drugs influenced by the SLC25A20 gene
When should I seek medical advice?
There is not a broadly confirmed role for this gene in guiding medication choices or dose changes. Speak with your doctor or pharmacist if you have unusual side effects, if a medicine seems to affect you differently than expected, or before making any changes to your treatment.