The PEX16 gene gives your cells instructions for making and maintaining peroxisomes, small structures that break down certain fats and help protect cells. This gene plays an important role in keeping the brain, liver, eyes, and hearing system working as expected. If the PEX16 gene does not work properly, peroxisomes may not form as they should, and fats and other substances can build up in cells. Pathogenic variants can cause a peroxisome biogenesis condition, often linked to developmental delay, low muscle tone, vision or hearing changes, and liver problems.
What is a gene?
Genes are sections of DNA that carry instructions your cells use to make molecules or regulate processes in the body. Some genes provide the information needed to produce proteins, the parts of cells that do much of the work. Other genes mainly control when certain processes happen, where they take place, and how strongly they operate. Together, genes affect how the body develops and functions, and they can influence how you respond to food, stress, or medications. For a more detailed look at this topic, you can learn more in the LearnHub.
Overview
PEX16Gene function
What if the gene works
The PEX16 gene helps cells build and maintain peroxisomes, small cell compartments that break down certain fats and help manage harmful byproducts. This supports normal cell function in many tissues, especially the brain and liver.
Risk
What if the gene does not work
Variants in the PEX16 gene can cause a Zellweger spectrum condition, often affecting development, muscle tone, vision, hearing, and the liver. Milder variants may cause later, less marked features, while more severe variants can appear earlier.
Treatment
What does that mean for your treatment
For people with a pathogenic variant in the PEX16 gene, no PEX16-specific treatment or drug choice approach is currently established; care is supportive and guided by symptoms. The PEX16 gene is being studied in broader peroxisomal disease research, including early work on gene-based treatments and ways to improve peroxisome function.
Conditions associated with PEX16
Gene function
What if the gene works
Inside your cells, the PEX16 gene helps build and maintain peroxisomes, small compartments that process certain fats and help manage cell chemicals. These compartments support everyday tasks in many tissues, including the liver and brain. Understanding what the PEX16 gene does starts with its role in forming the membrane around new peroxisomes.
One of the roles of the PEX16 gene is to help your cells create peroxisomes, which are small compartments that handle certain fats and cell chemicals. It helps set up membrane sites on the endoplasmic reticulum (a cell membrane network) where a new peroxisome can begin to form.
Through its protein, the PEX16 gene helps place important proteins into the peroxisome membrane. This gives each peroxisome the basic equipment it needs to bring in other proteins and do its routine work.
In daily cell function, the PEX16 gene helps maintain a steady supply of peroxisomes as cells grow and renew themselves. This supports ongoing fat processing and chemical balance across many tissues.
What is a variant?
A genetic variant is a minor change in a gene’s DNA sequence. These changes are common and help shape normal human diversity, including differences in appearance, metabolism, and the way the body responds to environmental factors. Many variants do not have any noticeable effect and are simply part of natural genetic variation. In some situations, though, a variant can change how a gene works more significantly and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
PEX16 gene variants can change the amount or shape of the PEX16 protein, so cells make too few peroxisomes or build them poorly. In practical terms, how PEX16 gene variants affect cell function often comes down to weaker placement of key proteins in the peroxisome membrane and less protein import into these cell compartments. Milder variants may leave some activity, while more severe variants can nearly stop peroxisome formation and are often linked to earlier or more marked Zellweger spectrum features.
How variants are linked to conditions
Pathogenic variants in both copies of the PEX16 gene cause Zellweger spectrum disorder, so doctors often describe PEX16 gene variants linked to Zellweger spectrum disorder as a rare inherited diagnosis rather than a risk factor. This condition can affect development, hearing, vision, the liver, and the nervous system, with presentation ranging from illness in infancy to milder forms recognized later. Older labels such as neonatal adrenoleukodystrophy and infantile Refsum disease are now usually included within the same spectrum.
A variant is not necessarily a diagnosis
Variants in genes are a usual feature of human biology and are widespread across the population. Most do not directly affect health and are simply one part of normal human variation. For many genes, having a variant associated with a condition points to a possible link, not a certain diagnosis, particularly when several genes and environmental influences also play a role. Still, in some situations, one well-described variant in a particular gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For PEX16, risk is mainly set by inheritance: a child is affected when they inherit harmful changes in both copies of the PEX16 gene, so the chance is higher when both parents carry one changed copy. Lifestyle, diet, or exercise do not meaningfully change this genetic risk.
Inheritance of PEX16 variants
PEX16-related conditions are inherited in an autosomal recessive pattern. In practical terms, how variants of the PEX16 gene are inherited usually means a person receives one altered copy from each parent. Parents who each carry one PEX16 gene variant are often unaffected themselves, and with each pregnancy there is a 25% chance the child will inherit both altered copies, a 50% chance the child will be a carrier, and a 25% chance the child will inherit neither altered copy.
What does my PEX16 result mean for my family?
For families with a disease-causing change in the PEX16 gene, the pattern is usually recessive, which often means parents carry the change without having symptoms themselves. Brothers and sisters may also be affected or may be healthy carriers, and other relatives could be carriers too. This can matter for family planning, because two carriers can have a child with the condition.
Genetic information
Genetic testing
How you find out about variants
For the PEX16 gene, genetic testing – how you find out about variants – usually involves a blood or saliva sample. A lab reads the DNA code in the PEX16 gene, often as part of a larger panel or exome test, to look for variants that may help confirm or rule out a genetic condition.
When should I consider getting a genetic test?
Genetic testing for the PEX16 gene may be worth considering if a baby or child has signs of a peroxisome condition, such as very low muscle tone, feeding problems, seizures, liver problems, hearing or vision loss, or delayed development. It can also help when there is a family history of this kind of inherited condition or a previous affected pregnancy.
A genetic result is only one part of your health story
Genetic findings can provide useful insight, but how much they reveal depends on the condition and on the kind of variant involved. Over time, many factors also shape how the body works, including lifestyle, environment, age, and medical history. For some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is best understood alongside other parts of care. In other situations, a genetic result may offer a clear answer. In areas such as medication response, these results can also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body responds to medicines. Some people break down a drug more slowly or more quickly, while others may be more or less sensitive to its effects. This helps explain why the same treatment can work well for one person, cause side effects in another, or seem to have less effect in someone else.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences shape a person’s response to medicines. It looks at gene and drug patterns to better understand why the same treatment can work differently from one person to another. For many medications, genes influence both how strongly a drug works and how the body processes it. This information can support more informed, more personalized treatment decisions. You can read more about this topic in the LearnHub.
Drugs influenced by the PEX16 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choices, so questions about medicines, side effects, or changes in your health are best discussed with your doctor.
History
PEX16 entered the genetics literature during efforts to understand inherited peroxisome biogenesis conditions, including Zellweger spectrum conditions. Initially understood only through visible traits, later recognized as tied to a specific gene, this work helped connect one of the earlier peroxisome complementation groups to PEX16 in the late 1990s. From these first observations, research expanded steadily, with cell studies showing that changes in the PEX16 gene could disrupt normal peroxisome formation. Over time, descriptions became more precise as scientists clarified where PEX16 acts during peroxisome assembly. These historical steps shaped today’s understanding of PEX16 as part of the broader story of how peroxisomal conditions were mapped from clinical patterns to specific genes.