The CLDN23 gene helps make claudin-23, a protein that helps seal the spaces between neighboring cells, especially in tissues that need a steady protective barrier. This gene plays an important role in keeping those cell-to-cell barriers organized, so if it does not work well, tissues may become less tightly sealed and cell growth signals may shift. Researchers have paid attention to the CLDN23 gene in stomach and colorectal cancers, where reduced activity has been linked to some tumors.
What is a gene?
Genes are stretches of DNA that hold instructions your cells use to make molecules or direct processes in the body. Some genes carry the information needed to produce proteins, the parts of cells that do the work. Other genes mainly regulate when certain processes happen, where they take place, and how strongly they operate. Together, genes affect how the body grows and works, and they can influence how you respond to food, stress, or medications. You can find more on this topic in the LearnHub.
Overview
CLDN23Gene function
What if the gene works
The CLDN23 gene helps make a protein in tight junctions, which seal neighboring cells together. This supports body linings such as the gut and helps control what passes between cells.
Risk
What if the gene does not work
Milder to more severe variants in the CLDN23 gene can weaken claudin 23, a tight junction protein, so neighboring cells seal less effectively and control movement of water and small molecules between them less precisely.
Treatment
What does that mean for your treatment
No treatment or management approach is currently established specifically for pathogenic or loss-of-function variants in the CLDN23 gene. The CLDN23 gene is being studied mainly as a possible cancer biomarker, especially in digestive tract tumors, rather than as a guide for current drug choice.
Gene function
What if the gene works
In tissues that line organs and body surfaces, the CLDN23 gene helps neighboring cells stay closely linked. Its protein becomes part of tight junctions, the seals between cells. These seals help body surfaces stay organized and control what passes through the spaces between cells.
The CLDN23 gene helps build tight junctions, which act like seals between neighboring cells. These seals keep cell layers linked so surfaces such as the gut lining can stay neat and continuous.
Its protein helps control what moves through the tiny spaces between cells. This is a key part of how the CLDN23 gene helps cells stay sealed together while still allowing limited passage of water and small dissolved substances.
This protein supports the organized layout of epithelial cells, the cells that line body surfaces and organs. By reinforcing contact points between neighbors, it helps these cell layers keep their shape and orientation.
What is a variant?
Genetic variants are small changes in the DNA sequence of a gene. They are common and help shape normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many have no noticeable effect and simply represent natural genetic variation. In some cases, though, a variant may change how a gene functions more substantially and can contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Some CLDN23 gene variants slightly alter the claudin-23 protein, so it is less stable, reaches the cell surface less efficiently, or interacts less well with nearby junction proteins. More disruptive variants can shorten the protein or stop it from being placed in the cell membrane, leading to a much larger loss of function. This range from milder to more severe variants can shape how much cellular activity remains.
How variants are linked to conditions
At present, the CLDN23 gene does not yet have a broadly confirmed link to a specific health condition, so information about how CLDN23 gene variants are linked to conditions may change as research develops. If you have a confirmed variant in the CLDN23 gene, your doctor or genetic counselor can explain what that result means in the context of your own health and family history.
A variant is not necessarily a diagnosis
Genetic variants are a common and normal feature of human biology. Most do not directly affect health and instead represent part of the natural range of human diversity. For many genes, having a variant associated with a condition points to a possible link rather than a certain diagnosis, particularly when several genes and environmental influences 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 isn't yet broadly confirmed evidence on specific factors that increase or reduce health risk related to the CLDN23 gene. If testing shows a change in CLDN23, its meaning often depends on the exact variant and your personal and family history.
Inheritance of CLDN23 variants
For CLDN23, there is not yet a broadly confirmed disease specific inheritance pattern, so how CLDN23 gene variants are inherited in relation to a defined genetic condition is still being clarified. The CLDN23 gene is located on chromosome 8, which is an autosome rather than a sex chromosome. That means each person usually has two copies of the CLDN23 gene, with one inherited from each parent.
What does my CLDN23 result mean for my family?
There is not yet a broadly confirmed inherited condition linked to the CLDN23 gene in the way seen with some other genes. That means a CLDN23 result usually does not give clear, established information about what relatives may also carry or develop. If your report includes a specific CLDN23 finding, a genetics specialist can explain what it may mean for your family based on the exact result.
Genetic information
Genetic testing
How you find out about variants
Testing for variants in the CLDN23 gene usually uses a blood or saliva sample. CLDN23 genetic testing reads the gene's DNA code to look for changes, often as part of a multigene panel or broader sequencing test. Results may show a benign variant, a disease-causing variant, or a variant of uncertain significance.
When should I consider getting a genetic test?
There is not yet a broadly established reason to order genetic testing specifically for the CLDN23 gene. Decisions about testing are usually based on your symptoms and family history, together with a doctor or genetic counselor.
A genetic result is only one part of your health story
A genetic result can provide useful insight, although how much it reveals varies by the condition and the specific type of variant. Over time, many factors, including lifestyle, environment, age, and medical history, also shape how the body functions. For some conditions, especially those influenced by many genes, genetic information offers context rather than certainty and is most helpful when considered alongside other parts of care. In other situations, a genetic result may give a clear answer. In areas like 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. Small differences in DNA can change how the body absorbs, breaks down, moves, or responds to a drug, so the same treatment may work better for one person than for another. This is common and can influence how much benefit someone gets from a medicine or how sensitive they are to side effects.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences can affect the way people respond to medicines. It looks at gene and drug patterns to help explain why the same treatment may work differently from one person to another. For many medications, genes influence either how strongly a drug works or how the body processes it. This information can support treatment decisions that are more informed and more individualized. You can read more about this topic in the LearnHub.
Drugs influenced by the CLDN23 gene
When should I seek medical advice?
There is not currently a broadly confirmed role for this gene in guiding how medicines are chosen or used, so general questions about treatment, side effects, or your health are best discussed with your doctor.