The SELENON gene helps muscle cells cope with everyday strain and keep calcium balance steady, which supports normal muscle strength, posture, and breathing. If this gene does not work properly, a person may develop SELENON-related myopathy, a condition that can cause muscle weakness, a stiff spine, delayed motor milestones, and breathing problems that often begin in infancy or childhood. Pathogenic variants in the SELENON gene are a known genetic cause of this muscle condition. Many other variants in this gene are harmless and do not cause disease.
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 directions for producing proteins, the parts of cells that do much of the work. Other genes are mainly involved in controlling when certain processes happen, where they happen, and how active they are. Taken together, genes affect how the body develops and functions, and they can also influence how you respond to food, stress, or medications. For a deeper look at this topic, you can read more in the LearnHub.
Overview
SELENONGene function
What if the gene works
The SELENON gene helps muscle cells manage calcium, which they need to contract and relax normally. It also supports muscle growth and protection from cell stress.
Risk
What if the gene does not work
Variants in the SELENON gene can cause a muscle condition with early weakness, poor head or trunk control, and spine stiffness. Breathing muscles are often affected, especially during sleep. Milder and more severe variants can change onset and severity.
Treatment
What does that mean for your treatment
No SELENON-specific treatment or drug selection approach is currently established. Care is supportive, with close breathing monitoring and timely respiratory support often shaping management, and the SELENON gene is being studied in early-stage research as a possible treatment target in muscle disease.
Conditions associated with SELENON
Gene function
What if the gene works
Your muscles need steady calcium and a stable cell environment to work well. A key part of that support comes from the SELENON gene. Its protein sits in the endoplasmic reticulum (a cell compartment that stores calcium and helps proteins take their working shape). This is especially important in muscle tissue.
The SELENON gene helps manage calcium levels in a storage area inside the cell. In muscle cells, this steady calcium supply helps muscles tighten and relax in a controlled way.
Its protein helps keep the cell's internal environment steady during normal energy use. This can reduce oxidative stress (a type of chemical strain inside cells) as muscles work.
Inside the endoplasmic reticulum (a cell compartment that helps proteins take shape), SELENON supports conditions that help proteins fold properly. This helps cells keep routine work running smoothly.
In active muscle, the SELENON gene supports cell maintenance during growth, repair, and repeated use. Understanding the SELENON gene's function in muscle cells helps explain how muscles stay steady over time.
What is a variant?
A genetic variant is a minor change in a gene’s DNA sequence. These changes are common and help explain normal differences among people, such as appearance, metabolism, or the way the body responds to environmental influences. Many variants do not have any noticeable effect and are simply part of natural genetic variation. In some situations, though, a variant changes how a gene works more substantially and may contribute to, or cause, a genetic condition.
Genetic variants
What if the gene does not work
Variants in the SELENON gene can reduce how much selenoprotein N a cell makes or change its shape so it becomes unstable and cannot work properly in the endoplasmic reticulum, the cell’s protein processing network. Some SELENON gene variants have a partial effect, while more disruptive variants can leave little or no working protein. This difference often shapes how early SELENON-related muscle weakness appears and how marked breathing or spine problems become.
How variants are linked to conditions
Pathogenic variants in the SELENON gene cause SELENON-related myopathy, historically called SEPN1-related myopathy, an inherited muscle condition. This group includes rigid spine muscular dystrophy and some congenital myopathies, and the link between SELENON gene variants and congenital myopathy is well established. Many affected people develop muscle weakness in childhood, often with spine stiffness, scoliosis, and breathing muscle involvement.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are commonly found in the general population. Most do not directly affect health and simply reflect natural human diversity. For many genes, carrying a variant associated with a condition indicates a possible link rather than a confirmed diagnosis, especially when several genes and environmental factors play a role. In some situations, though, a single well-characterized variant in a particular gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For SELENON-related muscle conditions, risk is mainly set by the gene changes inherited at birth. When both parents carry a harmful SELENON variant, each child has a 1 in 4 chance of having the condition. Specific lifestyle or environmental factors that change this risk are not clearly established.
Inheritance of SELENON variants
SELENON-related conditions are inherited in an autosomal recessive pattern. In practical terms, inheritance of SELENON gene variants usually means a child is affected only when they inherit one disease-causing variant from each parent. Parents who each carry one SELENON variant are usually unaffected themselves, and with each pregnancy there is a 25% chance of having an affected child, a 50% chance of having a child who is a carrier, and a 25% chance of having a child with neither variant. Because the SELENON gene is on an autosome, this pattern is the same for males and females.
What does my SELENON result mean for my family?
For families with a disease-causing change in the SELENON gene, the condition is usually passed down in a recessive pattern. This often means parents are healthy carriers, brothers and sisters may also be affected or be carriers, and close relatives may want to learn whether the same gene change runs in the family. Children of someone with SELENON-related disease will usually be carriers unless the other parent also carries a disease-causing SELENON change.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a variant in the SELENON gene, clinicians use SELENON genetic testing on a blood or saliva sample. A laboratory reads the DNA in this gene and checks for variants that may help explain a muscle condition or confirm a diagnosis when symptoms fit.
When should I consider getting a genetic test?
Genetic testing for the SELENON gene can be worth considering when someone has early muscle weakness, a stiff spine, late sitting or walking, or unexplained breathing problems, especially during sleep. It can also help if these signs run in the family or a doctor suspects a SELENON-related muscle condition.
A genetic result is only one part of your health story
A genetic result can provide helpful insight, but how much it can tell you varies with the condition and the type of variant involved. Over time, many factors, including lifestyle, environment, age, and medical history, also shape how the body functions. For some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is best understood together with other parts of care. In other situations, a genetic result may offer a clear answer. In areas such as medication response, genetic results can also help make individual experiences easier to understand.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. People process the same drug in different ways, so one person may get the expected benefit while another may notice less effect or more side effects. These differences are common and can influence how quickly a medicine is broken down, how strongly it works, or how sensitive the body is to it. Medication response also depends on other factors, including age, liver and kidney function, and other medicines being taken.
What is Pharmacogenetics?
Pharmacogenetics examines how inherited genetic differences affect the way people respond to medications. It studies gene-drug relationships to help explain why the same treatment can work differently in different people. For many medicines, genes influence how powerfully a drug works or how the body handles it. This information can support more informed, personalized treatment choices. More detail on this topic is available in the LearnHub.
Drugs influenced by the SELENON gene
When should I seek medical advice?
There isn't yet a broadly confirmed role for this gene in guiding medicine choice or dose. If you have concerns about symptoms, side effects, or how a treatment may affect your overall health, it is best to discuss them with your doctor.
History
SELENON entered medical genetics in the early 2000s, when researchers linked changes in this gene to rigid spine muscle weakness and several related childhood muscle conditions. Initially understood only through visible traits, later recognized as tied to a specific gene, these diagnoses began to be grouped under a shared cause rather than treated as completely separate illnesses. Building on this early work, scientists found that SEPN1-related myopathy and other overlapping muscle conditions were part of the same spectrum. The name later shifted from SEPN1 to the SELENON gene as gene naming became more standardized. Over time, descriptions became more precise. This history helped connect families’ experiences with a clearer genetic explanation and improved how these conditions were classified.