The CDH1 gene gives cells instructions for E cadherin, a protein that helps neighboring cells stay attached and organized, especially in the stomach lining and breast tissue. This gene plays an important role in keeping tissue structure stable as cells grow and repair. If the gene does not work properly, cells may separate too easily and grow in a less controlled way. Harmful inherited variants in the CDH1 gene are linked to a hereditary form of diffuse stomach cancer and can also increase the chance of lobular breast cancer.
What is a gene?
Genes are stretches of DNA that hold instructions your cells use to make molecules or regulate processes in the body. Some genes provide the directions for making proteins, the parts of cells that do much of the work. Others mainly help determine when certain processes happen, where they happen, and how strongly they run. Together, genes affect how the body develops and works, and they can influence how you respond to food, stress, or medications. For a deeper look at this topic, you can find more in the LearnHub.
Overview
CDH1Gene function
What if the gene works
The CDH1 gene helps neighboring cells stick together, especially in tissues that line organs and the skin. This supports tissue shape, cell communication, and more controlled growth.
Risk
What if the gene does not work
Changes in the CDH1 gene are linked to hereditary diffuse gastric cancer and lobular breast cancer. Milder and more severe variants can affect how much cell to cell sticking is lost, which may influence when these cancers appear.
Treatment
What does that mean for your treatment
A pathogenic variant in the CDH1 gene can change management, with prophylactic total gastrectomy often considered because early cancer spots may be missed on endoscopy. If surgery is deferred, expert endoscopic surveillance may help guide timing. For breast cancer risk, care may include MRI screening and sometimes discussion of risk reducing mastectomy, but no CDH1-specific drug choice is established.
Conditions associated with CDH1
Gene function
What if the gene works
Many of your body’s surfaces and linings depend on the CDH1 gene to keep cells connected and orderly. It is especially important in epithelial tissues, such as the stomach lining, breast ducts, and skin. Understanding how the CDH1 gene helps cells stick together makes it easier to see how these tissues hold their shape and work smoothly.
The CDH1 gene helps neighboring cells attach to each other through its protein, E-cadherin. This creates strong links that let cells form stable sheets instead of acting like separate, loose cells.
By keeping cells connected, this gene helps tissues stay neatly arranged and maintain polarity (their built-in top and bottom orientation). That structure supports normal function in places like the stomach lining, breast ducts, and other body surfaces.
CDH1 also helps cells sense when they are touching their neighbors. These contact signals support controlled growth and help cells stay in the right place during everyday tissue renewal.
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, and the way the body reacts to environmental factors. Many variants do not have any noticeable effect and simply represent natural genetic variation. Sometimes, though, a variant changes how a gene works enough to contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Many variants in the CDH1 gene weaken or stop E-cadherin, a protein that helps cells stick together, so cells separate more easily. This is how variants in the CDH1 gene change how cells stick together: some milder variants alter the protein’s shape or stability, while more severe variants can stop a working protein from being made. More disruptive pathogenic variants are often linked to earlier onset in the cancer syndromes associated with the CDH1 gene.
How variants are linked to conditions
Pathogenic variants in the CDH1 gene cause hereditary diffuse gastric cancer, an inherited cancer condition linked to a higher chance of diffuse stomach cancer and lobular breast cancer. This well established CDH1 gene link to hereditary diffuse gastric cancer and lobular breast cancer is the main condition association seen in clinical genetics. Some families with a CDH1-related condition also have cleft lip or cleft palate.
A variant is not necessarily a diagnosis
Variants in genes are a usual part of human biology and are common across the general population. Most do not have a direct impact on health and simply reflect normal human diversity. For many genes, carrying a variant associated with a condition indicates a possible link rather than a clear diagnosis, especially when more than one gene and environmental factors contribute. In some situations, though, a single well-characterized variant in a particular gene can be enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For CDH1, risk is driven mainly by the inherited gene change itself, especially for diffuse stomach cancer and lobular breast cancer. Family history and sex can affect which cancer is more likely, but specific lifestyle factors that clearly change this risk are not well established, so careful monitoring is usually the key step.
Inheritance of CDH1 variants
CDH1-related cancer risk is usually inherited in an autosomal dominant pattern. That means a person with a disease-causing variant in the CDH1 gene has a 50% chance of passing it on to each child, regardless of sex. In practical terms, when people ask how variants of the CDH1 gene are inherited, the answer is that one changed copy from either parent can be enough to run in a family. Not everyone who inherits the variant will develop the same health problems, but the inheritance pattern itself is well established.
What does my CDH1 result mean for my family?
A disease-causing change in the CDH1 gene often runs in families in a dominant pattern, so close relatives such as parents, brothers, sisters, and children may also carry the same change. Each child of someone with a CDH1 variant has a 50% chance of inheriting it. This can matter because some family members may also have a higher risk of certain cancers, especially diffuse stomach cancer and lobular breast cancer.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a variant in the CDH1 gene, a lab can analyze DNA from a blood sample, saliva, or cheek swab. CDH1 genetic testing checks the gene’s code for changes linked to hereditary diffuse gastric cancer and lobular breast cancer. Results may show a harmful variant, a benign variant, or an unclear result.
When should I consider getting a genetic test?
Consider CDH1 testing if you or close relatives have had diffuse stomach cancer, lobular breast cancer, or several family members with these cancers, especially at younger ages. It can also matter when the family history includes both stomach and breast cancer.
A genetic result is only one part of your health story
Genetic results can provide useful insight, although what they can tell you varies with the condition and the type of variant involved. Over time, many other factors also shape how your body works, including lifestyle, environment, age, and medical history. For some conditions, especially those influenced by many genes, genetic information offers context rather than certainty and makes the most sense when considered alongside other parts of care. In other situations, a genetic result can give a clear answer. In areas like medication response, genetic results may help put a person’s experiences into perspective.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Small inherited differences can change how the body 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 differences in a person’s genes can affect the way they respond to medications. It focuses on the relationship between genes and drugs to help explain why the same treatment may work differently in different people. For many medicines, genes can influence how much effect a drug has or how the body handles it. This information can support more informed, more personalized treatment choices. More on this topic is available in the LearnHub.
Drugs influenced by the CDH1 gene
When should I seek medical advice?
There isn’t yet a broadly confirmed role for this gene in guiding medication response, so if you have concerns about side effects, treatment changes, or how a medicine is working, it is best to discuss them with your doctor.
History
The CDH1 gene entered cancer genetics in the 1990s, when researchers linked inherited variants in this gene to families with diffuse stomach cancer appearing across generations. This was a major step because it helped explain a pattern that had long been seen in some families but not fully understood. In recent decades, awareness of this gene’s role has grown as experts also connected CDH1 variants with an increased chance of lobular breast cancer in some people. As genetic testing became more widely used, the CDH1 gene became an important part of care for families with hereditary diffuse gastric cancer. These discoveries also changed medical guidelines, with more attention to family history, counseling, and early risk management.