The SOST gene helps control how quickly new bone is made by acting as a natural brake on bone building. If it does not work, bones can become unusually thick and dense, especially in the skull, jaw, and hands. This can lead to bone pain, changes in facial shape, hearing problems, or pressure on nearby nerves. Research on the SOST gene also helped lead to newer osteoporosis treatments that increase bone formation by blocking its protein.
What is a gene?
Genes are stretches of DNA that carry instructions your cells use to make molecules or regulate processes in the body. Some genes hold the instructions for making proteins, which are the working parts of cells. Others mainly help determine when certain processes happen, where they happen, and how strongly they run. Together, genes influence how the body develops and works, and they can shape how you respond to food, stress, or medications. For a more detailed look at this topic, you can find more in the LearnHub.
Overview
SOSTGene function
What if the gene works
The SOST gene helps control how much new bone your body makes. It makes sclerostin, a protein that tells cells that build bone to slow down. This helps keep bone growth balanced and supports normal bone strength.
Risk
What if the gene does not work
When the SOST gene works too little, bones can become unusually dense and overgrown, often affecting the skull and jaw. Milder to more severe variants can change when problems appear and how much bone overgrowth and nerve pressure develop.
Treatment
What does that mean for your treatment
No treatment or drug choice is currently tailored to pathogenic variants in the SOST gene; care is guided by symptoms and complications rather than the gene result itself. The SOST gene is an important drug target in bone medicine, and therapy that blocks sclerostin, such as romosozumab, is used for osteoporosis, not to treat the high bone mass conditions caused by SOST variants.
Conditions associated with SOST
Gene function
What if the gene works
Your bones are constantly being renewed, and the SOST gene helps keep that process balanced. It gives bone cells a braking signal so new bone is added at the right pace. Understanding what the SOST gene does in bone helps explain how your skeleton stays strong while keeping its usual shape.
The SOST gene helps limit how strongly bone-building cells are turned on. This keeps new bone formation in balance with your body's normal bone renewal.
Through the sclerostin protein, the SOST gene dampens WNT signals, which are messages that encourage bone building. This gives your skeleton a way to fine-tune growth rather than push it nonstop.
Your skeleton is always replacing small areas of older bone with new bone. In this process, the SOST gene helps keep turnover measured, supporting bone strength and the usual internal structure of bone.
Bone cells buried within bone can sense everyday strain from walking, lifting, and movement. Within this network, the SOST gene helps adjust bone-building signals to match those routine forces.
What is a variant?
A genetic variant is a minor difference in the DNA sequence within a gene. These differences are common and help explain normal variation among people, including traits such as appearance, metabolism, and the way the body responds to environmental factors. Many variants do not produce any noticeable effect and are simply part of natural genetic diversity. Sometimes, though, a variant changes how a gene works to a greater extent and can contribute to, or cause, a genetic condition.
Genetic variants
What if the gene does not work
Variants in the SOST gene can reduce how much sclerostin is made, change its shape, or block its release from bone cells. This is how variants in the SOST gene affect bone growth: with less working sclerostin, bone-forming signals stay more active. Milder variants may leave some protein activity, while more severe loss-of-function variants, which reduce or stop protein activity, can leave little or none and often link to greater bone mass, including sclerosteosis or van Buchem disease.
How variants are linked to conditions
Pathogenic variants in the SOST gene cause sclerosteosis, a rare inherited condition with progressive bone overgrowth, often affecting the skull, jaw, and height. Changes involving the SOST region are also linked to van Buchem disease, another inherited bone thickening condition. These SOST gene variants and bone overgrowth conditions are well established in human genetics and are not the same as common gene changes that only shift risk.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of human biology and are widely found across the general population. Most do not directly affect health and instead reflect natural human diversity. For many genes, carrying a variant associated with a condition points to a possible link rather than a definite diagnosis, especially when several genes and environmental factors play a role. In some situations, though, a single well-characterized variant in a particular gene can by itself confirm a diagnosis.
Are there things that can increase or change my risk?
There is not yet broadly confirmed evidence on specific factors that increase or reduce health risk related to the SOST gene itself. For people who carry a disease-causing change in SOST, the chance of developing the related bone condition is driven mainly by the inherited gene change rather than lifestyle.
Inheritance of SOST variants
SOST-related conditions are typically inherited in an autosomal recessive pattern. This means a person usually inherits one altered copy of the SOST gene from each parent, and parents who each carry one copy are often unaffected; 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 who inherits neither altered copy. In practical terms, how SOST gene variants are inherited usually means the condition can appear in a child even when there is no obvious family history.
What does my SOST result mean for my family?
For SOST, family implications are usually discussed in the setting of a rare bone condition that follows a recessive inheritance pattern. This often means parents are healthy carriers, brothers and sisters may also be carriers or may have the condition, and children are usually carriers unless the other parent also carries a changed SOST copy. Close relatives may want to learn whether the same result runs in the family.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a variant in the SOST gene, doctors use genetic testing for SOST variants on a blood sample or cheek swab. A lab reads the DNA code and compares the SOST gene with the usual sequence to identify changes.
When should I consider getting a genetic test?
Genetic testing for the SOST gene may be worth considering when someone has unusually high bone density, overgrowth of the jaw or skull, repeated facial nerve symptoms, or a family history of these findings. In that setting, testing can help confirm whether an inherited SOST-related bone condition is the cause.
A genetic result is only one part of your health story
Genetic results can be informative, although what they can tell you varies with the condition and the specific type of variant involved. Over time, how the body works is also shaped by many other factors, including lifestyle, environment, age, and medical history. In some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is best considered 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, seem less effective for another, or cause more side effects in someone else.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences can shape a person’s response to medications. It focuses on connections between genes and drugs to better explain why the same treatment can work differently from one person to another. With many medicines, genes influence either how strongly a drug works or how the body handles it. This information can support more informed and more individualized treatment decisions. More on this topic is available in the LearnHub.
Drugs influenced by the SOST gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication response, so questions about your medicines, side effects, or general health concerns are best discussed with your doctor.
History
Throughout history, people have described features that hinted at this gene. A major step came when doctors studied families with rare inherited conditions marked by unusually dense bones, including sclerosteosis and van Buchem disease. In the late 1990s and early 2000s, researchers linked these conditions to changes affecting the SOST gene, helping explain a long-standing medical puzzle. Building on this early work, scientists identified the protein sclerostin and recognized its importance in bone research. That discovery reshaped how bone formation was studied and later supported the development of new osteoporosis treatments that target this pathway. Over time, the SOST gene became an important example of how rare inherited conditions can open the door to broader advances in medicine.