The S100A8 gene helps make a protein used by certain white blood cells to guide inflammation and respond to infection or tissue injury. If it does not work as it should, inflammatory signals may become less well controlled. Together with the S100A9 gene, it forms calprotectin, a protein doctors measure because high levels can point to inflammation, especially in the gut. Some people first learn about this gene when a stool calprotectin test is used to look for bowel inflammation.
What is a gene?
Genes are stretches of DNA that give your cells instructions for making molecules or directing activities in the body. Some genes carry the information needed to make proteins, which are the working parts of cells. Other genes mainly regulate when certain processes take place, where they occur, and how strongly they run. Together, genes affect how the body develops and functions, and they can also influence how you respond to food, stress, or medications. For a more detailed look at this topic, you can find additional information in the LearnHub.
Overview
S100A8Gene function
What if the gene works
The S100A8 gene helps certain white blood cells respond to infection and tissue injury. Its protein supports inflammation signaling and often works with S100A9 to guide immune cells where they are needed.
Risk
What if the gene does not work
Changes in the S100A8 gene can range from mild to more severe and may weaken calprotectin formation, metal binding, and inflammatory signaling. This can alter how some white blood cells respond to stress or microbes.
Treatment
What does that mean for your treatment
A pathogenic or loss-of-function variant in the S100A8 gene does not currently point to a gene-specific treatment or change in drug choice in clinical guidelines. The S100A8 gene is being studied mainly as an inflammation biomarker, often alongside S100A9, and as a possible drug target in some inflammatory conditions and cancers.
Gene function
What if the gene works
The S100A8 gene helps white blood cells respond when the body detects germs or tissue stress. Its protein often pairs with the S100A9 protein, especially in neutrophils and monocytes. Together, they support early immune defense, inflammation signals, and control of certain metals that microbes use.
The S100A8 protein binds calcium, a mineral cells use for signaling. This changes the protein’s shape and helps it interact with partner proteins at the right time.
The S100A8 gene is especially active in neutrophils and monocytes, two early response white blood cells. It helps these cells react to signs of germs or tissue stress.
Outside cells, S100A8 can act as a messenger that alerts nearby immune cells. This supports the S100A8 gene’s role in inflammation during the body’s early response.
S100A8 often joins with S100A9 to form calprotectin, a working protein pair. Together they can hold zinc and manganese, which helps limit nutrients that many microbes need.
What is a variant?
A genetic variant is a minor change in the DNA sequence within a gene. 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 do not cause any noticeable effect and simply represent natural variation in our genes. Sometimes, though, a variant can change how a gene works more clearly and may help cause or contribute to a genetic condition.
Genetic variants
What if the gene does not work
Variants in the S100A8 gene can change the shape, stability, or amount of the S100A8 protein, which may weaken how it binds calcium, pairs with S100A9, or interacts with cell signaling partners. Milder changes may slightly reduce protein activity, while more severe variants can sharply lower protein production or leave the protein unable to fold or work properly. This overview of how variants influence the S100A8 gene's function focuses on these cellular effects rather than a fixed health outcome.
How variants are linked to conditions
Current evidence does not yet show a broadly confirmed pattern of S100A8 gene variants linked to conditions in the way seen for many single gene diagnoses. Research has explored possible ties to inflammatory and immune related health patterns, but these findings have not established S100A8 as a gene with a widely accepted, specific genetic diagnosis, so anyone with a reported variant should interpret it with their doctor or genetic counselor.
A variant is not necessarily a diagnosis
Gene variants are a normal feature of human biology and are common throughout the general population. Most do not have a direct effect on health and simply represent natural variation among people. For many genes, carrying a variant associated with a condition indicates a possible link rather than a definite diagnosis, especially when multiple genes 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?
There is not yet broadly confirmed evidence on specific factors that clearly increase or reduce health risk related to the S100A8 gene itself. Many health outcomes linked with inflammation are shaped by a mix of genes, overall health, smoking, weight, infections, and other exposures, not by S100A8 alone. Anyone worried about personal risk should speak with a doctor or genetic counselor.
Inheritance of S100A8 variants
There is not yet a broadly confirmed Mendelian pattern for how S100A8 gene variants are inherited in a specific S100A8 related condition, so the answer to how S100A8 variants are inherited remains limited to what is established so far. The S100A8 gene is located on chromosome 1, which is an autosome. That means every person inherits one copy from each parent, regardless of sex.
What does my S100A8 result mean for my family?
There isn't yet a broadly confirmed inheritance pattern tied to a specific condition for S100A8, though this understanding can change as research develops. If you have a specific S100A8 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 health history.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for variants in the S100A8 gene usually uses a blood or saliva sample. A lab reads the DNA sequence, often as part of a larger panel or exome test, to identify changes and classify whether they are benign, uncertain, or linked to disease.
When should I consider getting a genetic test?
There isn't yet a broadly established S100A8-specific reason for genetic testing in routine care. Testing decisions are usually based on your overall symptoms, other test results, and family history, ideally with guidance from a doctor or genetic counselor.
A genetic result is only one part of your health story
A genetic finding can provide useful insight, but how much it explains depends on the condition and the type of variant involved. Many factors, including lifestyle, environment, age, and medical history, also shape how the body works over time. 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 can 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. Some people break down a drug more quickly, while others process it more slowly or may be more sensitive to its effects. This helps explain why the same treatment can work well for one person but not as well for another, or why side effects can differ. These differences are common and are one part of the bigger picture that shapes medication response.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences affect the way people respond to medications. It focuses on gene and drug patterns to help explain why the same treatment can work differently from one person to another. For many medicines, genes influence both how strongly a drug works and how the body processes it. This information can support more informed, more individualized treatment decisions. To explore this subject in greater detail, more information is available in the LearnHub.
Drugs influenced by the S100A8 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 any concerns about treatment, side effects, or your general health are best discussed with your doctor.
History
S100A8 entered the medical literature through studies of inflammation, where researchers identified a small protein in white blood cells and gave it several early names, including MRP8 and calgranulin A. Initially understood only through visible traits, later recognized as tied to a specific gene, it became part of a broader group of S100 genes mapped on chromosome 1. Over time, descriptions became more precise as scientists linked these earlier findings to the S100A8 gene itself. Its history is closely tied to work on inflammatory bowel disease, arthritis, and infection, where paired measurements with S100A9 helped establish its place in routine research and clinical testing. Scientific classifications changed as researchers learned more about the gene. Today, its historical path reflects the wider shift from naming proteins by where they were found to understanding them through genetics.