The SHMT1 gene helps your cells use folate, a B vitamin, to make and repair DNA. This gene plays an important role in turning serine into glycine, a step that supports healthy cell growth, especially in blood-forming tissues. If it does not work well, cells may have more trouble copying DNA and keeping folate balance steady. Most variants in the SHMT1 gene are linked to subtle metabolic differences rather than a clearly defined inherited condition.
What is a gene?
Genes are stretches of DNA that carry instructions your cells use to make molecules or to regulate processes in the body. Some genes hold the information needed to produce proteins, the parts of cells that do the work. Other genes mainly direct 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 shape how you respond to food, stress, or medications. For a deeper look at this topic, you can find more in the LearnHub.
Overview
SHMT1Gene function
What if the gene works
The SHMT1 gene helps cells use folate (vitamin B9) to move small chemical units needed to make DNA. This supports normal cell growth, repair, and steady handling of the amino acids serine and glycine.
Risk
What if the gene does not work
Variants in the SHMT1 gene can be mild or more severe. They may reduce how cells use serine and folate, lowering one-carbon units needed for DNA building and methylation (chemical tags that help control gene activity).
Treatment
What does that mean for your treatment
No treatment or management approach specific to pathogenic variants in the SHMT1 gene is currently established. The SHMT1 gene is being studied as a possible drug target and biomarker in folate metabolism and some cancers, but this has not led to treatment choices in clinical guidelines.
Gene function
What if the gene works
Your cells use the SHMT1 gene during routine chemical work that helps them grow and renew themselves. It moves small carbon pieces between serine, glycine, and folate. This supports folate metabolism and a steady supply of DNA building materials.
The SHMT1 gene helps your cells turn serine into glycine. During this step, it also moves a small carbon unit onto folate, which your cells reuse for other essential jobs.
Its protein supports folate metabolism by loading folate with one carbon pieces. This keeps a ready supply of working forms of folate that cells use in everyday cell chemistry.
The SHMT1 gene helps provide materials needed to make some of DNA's chemical letters, including thymidine and purines. This supports normal cell renewal in tissues that regularly replace old cells.
What is a variant?
A genetic variant is a minor change in the DNA sequence of a gene. These changes are common and are part of normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. In some cases, though, a variant can change how a gene functions more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
How variants influence the SHMT1 gene's function depends on whether a DNA change slightly lowers enzyme efficiency or more strongly disrupts the protein. Some variants may reduce how much SHMT1 is made, while others can change its shape, making it less stable or less able to bind vitamin B6 and folate related molecules it needs for one carbon transfer. Milder variants may leave some activity in place, while more severe variants can lead to a much larger loss of function.
How variants are linked to conditions
Research on how variants in the SHMT1 gene are linked to conditions is still developing, and this gene does not yet have a broadly confirmed connection to a specific health condition. If you have a reported change in the SHMT1 gene, your clinician or genetic counselor can interpret it in the context of your personal and family history.
A variant is not necessarily a diagnosis
Genetic variants are common across the general population and are a normal part of human biology. Most do not directly affect health and simply reflect natural differences among people. For many genes, having a variant associated with a condition points to a possible link rather than confirming a 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 the diagnosis.
Are there things that can increase or change my risk?
There isn't yet broadly confirmed evidence on specific factors that clearly increase or reduce health risk related to the SHMT1 gene. Some SHMT1 changes have been studied alongside folate intake and other genes involved in processing B vitamins, but these links are not strong enough to predict what will happen for one person.
Inheritance of SHMT1 variants
There is not yet a broadly confirmed Mendelian pattern for how SHMT1 gene variants are inherited in relation to a specific SHMT1 related condition. Current evidence has linked many SHMT1 gene changes more to small shifts in risk than to a single clearly inherited syndrome. In practical terms, SHMT1 gene inheritance still follows the usual rule for genes on the numbered chromosomes: you receive one copy from each parent. The SHMT1 gene is located on chromosome 17, an autosome, so inheritance is generally the same in males and females.
What does my SHMT1 result mean for my family?
There isn't yet a broadly confirmed inherited pattern tied to a specific health condition for SHMT1, so a SHMT1 result usually does not have the same clear family meaning seen with genes that cause a well-defined inherited condition. If you have a specific SHMT1 result and want to understand what it could mean for relatives, a doctor or genetic counselor can explain it in the context of your personal and family history.
Genetic information
Genetic testing
How you find out about variants
Testing for variants in the SHMT1 gene usually uses a blood or saliva sample. A lab reads the gene's DNA code to look for changes, and SHMT1 genetic testing can show whether a known variant is present, though results need to be interpreted in the context of your personal and family history.
When should I consider getting a genetic test?
There isn't yet a broadly established, SHMT1-specific clinical reason for testing. Decisions about genetic testing are usually based on your personal health history, family history, and the bigger picture of related genes, best discussed with 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 reveals depends on both the condition and the type of variant involved. Many factors, including age, lifestyle, environment, 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 may give a clear answer. In areas such as response to medications, genetic results can help put individual experiences into context.
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 a drug, moves it through the body, or responds at the target the drug is meant to affect. Because of this, the same treatment may work better for some people, have less effect in others, or cause more side effects in someone who is more sensitive. These differences are common and are one part of why medication response varies from person to person.
What is Pharmacogenetics?
Pharmacogenetics examines how differences in genes can affect the way a person responds to medications. By studying the relationship between genes and drugs, it helps explain why the same treatment may work differently from one person to another. With many medicines, genes can influence how strongly a drug works or how the body handles it. This information can help support treatment decisions that are more informed and more personalized. More information on this topic is available in the LearnHub.
Drugs influenced by the SHMT1 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding how medicines are chosen or adjusted, so concerns about side effects, treatment response, or new symptoms are best discussed with your doctor. Research on the SHMT1 gene has explored whether inherited changes may affect response or side effects with some cancer medicines that act on folate pathways, but this is not yet used routinely in everyday care.
History
SHMT1 came into view as researchers worked to map the body’s folate and one carbon pathways, which are systems cells use to handle building blocks needed for growth and repair. Initially understood through enzyme studies, it was later recognized as tied to a specific gene, helping connect older laboratory findings with modern genetics. As medical science evolved, so did understanding of this gene. Interest in SHMT1 grew further when scientists began studying how inherited variants might influence folate handling and related health patterns, especially in pregnancy, blood cell formation, and cancer research. Today, SHMT1 is mainly known within research and clinical genetics as part of the broader story of how folate metabolism supports everyday cell function.