The GSTM1 gene helps make an enzyme that clears some harmful chemicals, including byproducts of smoke, pollution, and normal cell stress. If it does not work, or if you carry the common GSTM1 deletion that removes the gene entirely, your body may be less efficient at handling some of these substances. This gene can play a role in how your body responds to environmental exposures and some medicines. Most people with a missing GSTM1 gene are healthy, but this change can slightly shift risk for certain conditions rather than cause a diagnosis on its own.
What is a gene?
Genes are stretches of DNA that give your cells instructions for making molecules or regulating processes in the body. Some genes provide the directions for producing proteins, the parts of cells that do much of the work. Other genes mainly control when certain processes happen, where they happen, and how active they are. Together, genes affect how the body develops and functions, and they can also influence how you respond to food, stress, or medications. To go further into this topic, you can find more in the LearnHub.
Overview
GSTM1Gene function
What if the gene works
The GSTM1 gene helps the liver and other tissues process certain chemicals from medicines, smoke, and normal cell activity. Its enzyme attaches a natural protective molecule to these substances, which helps the body clear them.
Risk
What if the gene does not work
If you carry a variant in the GSTM1 gene, effects can range from mildly reduced enzyme activity to a complete loss, often with the common gene deletion. This weakens the cell's ability to attach glutathione to certain chemicals for clearance.
Treatment
What does that mean for your treatment
No GSTM1-specific treatment or management approach is currently established in clinical guidelines, even for a loss-of-function variant. The GSTM1 gene is being studied as a biomarker for response to some cancer drugs and for how the body handles certain environmental chemicals.
Gene function
What if the gene works
Every day, your cells need to make ordinary chemicals safer before they build up. The GSTM1 gene gives cells instructions for an enzyme that attaches glutathione, a natural protective molecule, to certain reactive substances. Understanding how the GSTM1 gene works can make it easier to see how cells manage everyday chemical stress.
One of its main jobs is to link glutathione, a natural protective molecule, to reactive chemicals. This usually makes those chemicals less able to interfere with important parts of the cell.
After that tagging step, many compounds become easier for the body to process and remove. This supports routine cleanup of chemical byproducts made during normal cell activity.
GSTM1 also helps handle compounds formed during oxidative stress, a type of everyday wear and tear in cells. By processing these compounds, it supports a more stable cell environment.
Its enzyme can work on some medicines, pollutants, and components of smoke or diet after they enter the body. This is part of the body’s broader system for managing outside chemicals.
What is a variant?
A genetic variant is a slight difference in the DNA sequence within a gene. These differences are common and help shape normal human diversity, including variations in appearance, metabolism, and the way the body reacts to environmental influences. Many variants do not cause any noticeable effects and are simply part of natural genetic variation. At times, though, a variant can change how a gene works more significantly and may contribute to or lead to a genetic condition.
Genetic variants
What if the gene does not work
Many people carry a GSTM1 gene variant that removes the whole gene, often called the GSTM1 null genotype. In GSTM1 gene variants, a full deletion usually means no GSTM1 enzyme is made, while smaller DNA changes may produce an enzyme that is less stable or has lower activity inside cells. This creates a spectrum from milder reduction to complete loss of function, which can change how effectively cells process certain chemical byproducts.
How variants are linked to conditions
Current evidence on how variants in the GSTM1 gene are linked to conditions is still developing, and the GSTM1 gene does not yet have a broadly confirmed link to one specific health condition. If you have a reported change involving this gene, your doctor or genetic counselor can place it in the context of your personal and family health history.
A variant is not necessarily a diagnosis
Variants in genes are a routine feature of human biology and are widespread across the general population. Most do not directly affect health and simply contribute to normal 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 part. In other situations, though, one well understood variant in a particular gene may be enough to establish a diagnosis.
Are there things that can increase or change my risk?
For GSTM1, risk changes are usually small and depend on the bigger picture. A missing GSTM1 copy may slightly change how the body handles tobacco smoke, air pollution, and some workplace chemicals, which can affect risk for certain illnesses, including some cancers. Overall risk is also shaped by many other genes, smoking, alcohol use, diet, and daily exposures.
Inheritance of GSTM1 variants
For people looking into how GSTM1 gene variants are inherited, there is not a broadly confirmed Mendelian inheritance pattern tied to one specific GSTM1 related condition. Most well-known GSTM1 findings, including the common deleted copy, are studied as risk-influencing genetic differences rather than a single-gene diagnosis with a set dominant or recessive pattern. The GSTM1 gene is located on chromosome 1, which is an autosome, so you inherit one copy from each parent. In practice, a person may inherit a working copy, a deleted copy, or two deleted copies of the GSTM1 gene.
What does my GSTM1 result mean for my family?
There is not a broadly confirmed family pattern for GSTM1 tied to one specific inherited condition. GSTM1 results are usually about common genetic differences that can slightly affect risk or how the body handles certain chemicals, so what they mean for relatives depends on the exact result and the health concern being looked at.
Genetic information
Genetic testing
How you find out about variants
GSTM1 genetic testing uses a saliva or blood sample to check whether the GSTM1 gene is present or deleted, often reported as a “null” result when both copies are missing. Labs usually use DNA methods that read your genetic code and compare it with the expected GSTM1 sequence.
When should I consider getting a genetic test?
There isn't yet a broadly established, GSTM1-specific clinical reason for testing. Decisions about testing are best made with a doctor or genetic counselor, based on your health history, family history, and the reason testing is being considered.
A genetic result is only one part of your health story
Genetic results can offer useful insight, but how much they reveal depends on the condition and the specific type of variant involved. Over time, many other factors also shape how the body functions, including lifestyle, environment, age, and medical history. With 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 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. 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, have less benefit for another, or cause more side effects in someone else.
What is Pharmacogenetics?
Pharmacogenetics is the area of study focused on how differences in genes affect the way people respond to medications. It examines gene drug patterns to help explain why the same treatment may work differently from one person to another. With many medicines, genes can influence either how powerfully a drug works or how the body handles it. This information can support treatment decisions that are both better informed and more individualized. To look into this subject further, more information is available in the LearnHub.
Drugs influenced by the GSTM1 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 side effects, new symptoms, or how a treatment is working are best discussed with your doctor. Research on GSTM1 has looked at whether its common missing form may affect response or side effects with some medicines, but these findings are not used routinely in care.
History
Research on the GSTM1 gene grew out of broader work on glutathione S-transferase enzymes in the late 20th century, when scientists were sorting these genes into families with different patterns in the body. In recent decades, awareness of this gene’s role has grown. A key step came when researchers recognized that many people completely lack the GSTM1 gene because of a common inherited deletion, often called the GSTM1 null genotype. That finding made GSTM1 an important gene in population studies, especially research on smoking, air pollution, workplace exposures, and cancer susceptibility. Over time, scientists’ understanding of the gene’s function has changed, and GSTM1 remains one of the most frequently studied examples of how common genetic variation may influence health differences between people.