The PEX13 gene helps build and run peroxisomes, small parts of cells that break down certain fats and support brain, liver, and eye health. This gene plays an important role in moving the right proteins into these cell compartments so they can work properly. If you carry harmful variants in the PEX13 gene, peroxisomes may not work well, which can lead to a condition in the Zellweger spectrum. People with this condition may have low muscle tone, feeding problems, hearing or vision changes, liver disease, and delays in development.
What is a gene?
Genes are stretches of DNA that give cells instructions to make molecules or regulate processes in the body. Some genes carry the instructions for producing proteins, the parts of cells that do the work. Others mainly help determine when certain processes take place, where they occur, and how active they are. As a group, genes influence how the body develops and functions, and they can also shape how you respond to food, stress, or medications. You can find more detail on this topic in the LearnHub.
Overview
PEX13Gene function
What if the gene works
The PEX13 gene helps your cells build working peroxisomes, small compartments that break down certain fats. It also helps move needed proteins into these compartments, supporting normal cell growth and chemical balance.
Risk
What if the gene does not work
Variants in the PEX13 gene can cause Zellweger spectrum disorder, which may affect the brain, liver, hearing, and vision. Milder variants can lead to later, less severe symptoms, while more severe variants often cause problems starting in infancy.
Treatment
What does that mean for your treatment
For pathogenic variants in the PEX13 gene, no PEX13-specific treatment or drug selection approach is currently established. Care is based on the person’s symptoms and complications, using supportive treatments rather than a medicine chosen because of the PEX13 variant itself.
Conditions associated with PEX13
Gene function
What if the gene works
Inside your cells, the PEX13 gene helps keep peroxisomes working. Peroxisomes are small compartments that process certain fats and help manage chemical byproducts. A main job of this gene is to help the right enzymes enter these compartments so routine cell work can stay on track.
The PEX13 gene supports the making and maintenance of peroxisomes, which are small compartments inside cells. When this process runs normally, peroxisomes are ready to carry out their everyday jobs.
Its protein sits in the peroxisome membrane and helps arriving carrier proteins dock at the surface. This is a key step in how the PEX13 gene helps move enzymes into peroxisomes.
Once docking occurs, this gene works with other peroxisome proteins so needed enzymes can enter the compartment. With the right enzymes in place, cells can break down very long chain fats and handle hydrogen peroxide more effectively.
What is a variant?
A genetic variant is a minor difference in the DNA sequence within a gene. These differences are common and are part of normal human diversity, including variation in appearance, metabolism, and how the body reacts to environmental influences. Many variants do not cause any noticeable effects and simply represent natural genetic variation. Sometimes, though, a variant changes how a gene works more clearly and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the PEX13 gene can alter the protein's shape, stability, or ability to bind partner proteins, so proteins are not moved into peroxisomes, small cell compartments, as effectively. Many variants in the PEX13 gene that impair protein import into peroxisomes still leave some residual activity, while more disruptive variants can produce very little or no working protein. This range in functional loss often tracks with how early and how widely Zellweger spectrum disorder shows up.
How variants are linked to conditions
Pathogenic variants in the PEX13 gene cause PEX13-related Zellweger spectrum disorder, a rare inherited condition that can affect brain development, liver health, hearing, vision, feeding, and muscle tone. Severity can vary widely from one person to another. When a person has two disease-causing PEX13 variants, this finding can confirm the diagnosis.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are widely present in the general population. Most do not directly affect health and simply reflect natural human diversity. For many genes, carrying a variant associated with a condition indicates a possible link rather than a certain diagnosis, especially when multiple genes and environmental factors play a role. In some situations, however, 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 PEX13, risk is mainly set by the genetic changes themselves rather than by lifestyle. People usually develop a PEX13-related condition only when they inherit disease-causing changes in both copies of the gene, so family history and whether both parents carry a change matter most.
Inheritance of PEX13 variants
Variants in the PEX13 gene are inherited in an autosomal recessive pattern. This means a child usually inherits one changed copy of the PEX13 gene from each parent, and both parents are typically healthy carriers. When both parents carry a PEX13 gene variant, each pregnancy has a 25% chance of resulting in an affected child, a 50% chance of a child who is a carrier, and a 25% chance of a child with two working copies. In practical terms, how variants of the PEX13 gene are inherited is the same for sons and daughters.
What does my PEX13 result mean for my family?
For families affected by a PEX13-related condition, the pattern is usually recessive, which means parents are often healthy carriers. Brothers and sisters may also be affected or may be carriers, and other relatives could carry the same gene change without knowing it. This can matter for future pregnancies and for relatives who are planning children.
Genetic information
Genetic testing
How you find out about variants
PEX13 genetic testing looks for variants in the PEX13 gene using a blood sample, saliva, or cheek swab. A lab reads the gene’s DNA sequence to check for changes that may help explain symptoms or confirm a suspected peroxisomal condition. Results are interpreted alongside your medical history and, when relevant, family history.
When should I consider getting a genetic test?
Testing for the PEX13 gene may be considered if a baby or child has signs of this inherited condition, such as very low muscle tone, feeding problems, seizures, hearing or vision loss, or liver problems, or if it runs in the family. It can also clarify carrier status in relatives when a PEX13 change is already known.
A genetic result is only one part of your health story
Genetic results can provide useful insight, but how much they explain varies by the condition and the kind of variant involved. How the body functions over time is also shaped by many other factors, including lifestyle, environment, age, and medical history. In some conditions, especially those affected by many genes, genetic information provides context rather than certainty and is most helpful when viewed alongside other parts of care. In other situations, a genetic result can offer a clear answer. In areas such as medication response, genetic results can also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. This helps explain why the same treatment may work well for one person, have less effect in another, or cause more side effects in someone else. Part of the reason is that inherited differences can change how the body breaks down a drug, moves it through the body, or responds to it at its target.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences shape a person’s response to medications. By looking at relationships between genes and drugs, it helps clarify why the same treatment may work differently from one person to another. For many medicines, genes affect either how strongly a drug works or how the body processes it. This information can support more informed, individualized treatment decisions. More on this topic is available in the LearnHub.
Drugs influenced by the PEX13 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choice or dose, so general questions about medicines, side effects, or new symptoms are best discussed with your doctor.