GPA33 helps make a protein found mainly on the surface of cells lining the intestine, where it appears to support how these cells stick together and keep the gut lining organized. This gene is closely observed in clinical research due to its role in the cells of the colon and small intestine. If the GPA33 gene does not work as expected, the intestinal lining may be less stable at a cell level. In medicine, it is best known because GPA33 is often present in colorectal cancer cells and is being studied as a marker and treatment target.
What is a gene?
A gene is a section of DNA that carries instructions your cells use to make molecules or regulate processes in the body. Some genes hold the directions for making proteins, the parts of cells that do much of the work. Other genes mainly help determine when certain processes happen, where they happen, and how strongly they operate. Together, genes affect how the body develops 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
GPA33Gene function
What if the gene works
The GPA33 gene helps cells lining the gut stick together and maintain the intestinal barrier. Its protein sits on the cell surface and supports normal tissue organization in the bowel.
Risk
What if the gene does not work
Changes in the GPA33 gene can range from milder to more severe variants. When the GPA33 gene does not work properly, cells in the gut lining may have weaker cell-to-cell attachment and altered surface signaling.
Treatment
What does that mean for your treatment
No GPA33-specific treatment or management approach is currently established for people with pathogenic or loss-of-function variants in the GPA33 gene. In cancer research, GPA33 is being studied as a biomarker and as a target for antibody treatments, especially in colorectal cancer.
Gene function
What if the gene works
If you carry the GPA33 gene, it is mainly active in the lining of the intestine, where cells need to stay closely connected and well organized. Its protein sits on the cell surface and supports the everyday structure of this protective lining. This steady support is a key part of the role of the GPA33 gene in the gut lining.
The GPA33 protein helps neighboring intestinal cells recognize and hold their place next to each other. This supports a smooth, continuous lining rather than a loose or patchy surface.
By helping lining cells stay organized, GPA33 supports the gut barrier that separates the inside of the bowel from deeper body tissues. This helps everyday movement of food and fluid happen across a controlled surface.
Many cells in the intestine are replaced regularly, and GPA33 helps the mature surface layer remain orderly during this turnover. That steady arrangement supports day to day maintenance of the gut lining.
What is a variant?
A genetic variant is a minor change in a gene’s DNA sequence. These changes are common and are part of normal human diversity, including differences in appearance, metabolism, or the way the body reacts to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. Sometimes, though, a variant changes how a gene works more significantly and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Understanding how variants in the GPA33 gene affect protein function starts with the type of DNA change. Milder variants, such as some missense changes, may subtly alter the protein’s shape, stability, or delivery to the cell surface. More severe variants, including some nonsense, frameshift, or splice changes, can shorten the protein or greatly reduce how much of it the cell makes. This can lead to a weaker cell surface signal or, in some cases, little to no GPA33 protein.
How variants are linked to conditions
At present, the GPA33 gene does not have a broadly confirmed link to a specific inherited health condition, although research on how GPA33 gene variants are linked to conditions is still developing. If you carry a reported variant in the GPA33 gene, its meaning is best interpreted alongside your personal and family health history.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are common throughout the general population. Most do not directly affect health and instead reflect normal human diversity. For many genes, having a variant linked to a condition indicates a possible association rather than a confirmed diagnosis, especially when several genes and environmental factors also contribute. In some cases, though, a single well understood variant in a specific 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 GPA33 gene. Anyone with concerns about personal risk or test results related to GPA33 should speak with a doctor or genetic counselor.
Inheritance of GPA33 variants
There is not yet a broadly confirmed Mendelian inheritance pattern tied to a specific human condition for the GPA33 gene, so how GPA33 gene variants are inherited in relation to disease is still being worked out. The GPA33 gene is located on chromosome 1, which is an autosome. In general, that means you inherit one copy of the GPA33 gene from your mother and one copy from your father.
What does my GPA33 result mean for my family?
There isn’t yet a broadly confirmed inheritance pattern tied to a specific health condition for GPA33, though this understanding can change as research develops. If you have a specific GPA33 result and questions about what it could mean for your family, a doctor or genetic counselor can help explain it in the context of your personal and family history.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for GPA33 variants uses a blood sample, saliva sample, or cheek swab to look for DNA changes. A lab reads the GPA33 gene and compares it with the usual sequence to identify variants. Results may describe a variant as benign, uncertain, or pathogenic.
When should I consider getting a genetic test?
There is not yet a broadly established reason to get genetic testing specifically for the GPA33 gene. Testing decisions are usually based on your own health history, family history, and the bigger medical question a doctor or genetic counselor is trying to answer.
A genetic result is only one part of your health story
Genetic results can be informative, but how much they explain varies depending on the condition and the kind of variant involved. The way the body functions over time is also shaped by many factors, including age, environment, lifestyle, and medical history. For conditions influenced by many genes, genetic information usually offers context rather than certainty and is most useful when viewed together with other parts of care. In other situations, a genetic result may give a clear answer. In areas like 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 people respond to medicines. Small differences in DNA can change how the body absorbs, breaks down, transports, or responds to a drug, so the same treatment may work well for one person but less well for another. This is common and can influence both how much benefit a medicine provides and how sensitive someone may be to side effects.
What is Pharmacogenetics?
Pharmacogenetics looks at how differences in a person’s genes can shape their response to medications. It examines links between genes and drugs to help explain why the same treatment can work differently from one person to another. For many medicines, genes can affect both how strongly a drug works and how the body handles it. This information can support more informed, more individualized treatment choices. To explore this topic further, more information is available in the LearnHub.
Drugs influenced by the GPA33 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication response, so questions about medicines, side effects, or your overall health are best discussed with your doctor.
History
The GPA33 gene entered medical research through work on colorectal cancer, when scientists identified the A33 surface protein on many tumor cells and some normal cells in the intestine. In the 1990s, researchers began exploring how this gene works as part of efforts to better classify colorectal cancers and develop more targeted imaging and treatment approaches. From these first observations, research expanded steadily, especially in studies using antibodies designed to recognize the A33 protein. This made the GPA33 gene of interest not because it became widely known to the public, but because it offered a practical marker for laboratory and clinical research. Over time, its history has remained closely tied to gastrointestinal cancer studies and antibody based therapies.