The CSF1R gene gives instructions for a receptor that helps certain immune cells, especially the brain’s support cells called microglia, grow, survive, and care for brain tissue. This gene plays an important role in clearing cell debris and supporting white matter, so harmful variants can lead to a rare inherited brain condition with changes in thinking, behavior, walking, and movement. Most CSF1R variants have little effect, but a small number clearly disrupt how this gene works.
What is a gene?
A gene is a stretch of DNA that carries instructions your cells use to make molecules or regulate processes in the body. Certain genes hold the directions for producing proteins, which act as the cell's working parts. Other genes mainly help determine when specific processes happen, where they take place, and how strongly they occur. Together, genes affect how the body develops and works, and they can influence how you respond to food, stress, or medications. For a more detailed look at this topic, you can visit the LearnHub.
Overview
CSF1RGene function
What if the gene works
The CSF1R gene helps make a receptor on the cell surface that guides the growth and survival of immune cells called macrophages and brain cells called microglia. This supports normal immune cleanup, brain maintenance, and bone remodeling.
Risk
What if the gene does not work
Harmful variants in the CSF1R gene can cause an adult-onset brain condition affecting thinking, mood, behavior, and movement. Milder or more severe variants can change timing and severity, while variants in both copies may affect brain development and bone growth.
Treatment
What does that mean for your treatment
For people with a pathogenic variant in the CSF1R gene, allogeneic hematopoietic stem cell transplantation can be considered because it may slow decline in selected people with CSF1R-related ALSP, especially earlier in the course. Treatment decisions mainly depend on disease stage, MRI findings, and overall function. No CSF1R-targeted drug is currently established.
Conditions associated with CSF1R
Gene function
What if the gene works
In everyday body maintenance, the CSF1R gene helps a key group of immune cells grow, mature, and stay active. Its protein sits on the cell surface and receives chemical messages from nearby cells. Understanding what the CSF1R gene does in the body helps explain how tissues are cleaned up, supported, and renewed over time.
The CSF1R gene makes a cell surface receiver that picks up messages from CSF1 and IL34. These messages help certain immune cells survive, multiply, and mature at the right time.
This gene supports macrophages, the cleanup cells that remove germs, dead cells, and debris from tissues. That steady cleanup helps with healing and keeps everyday inflammation more controlled.
In the brain, the CSF1R gene helps maintain microglia, the brain's resident immune cells. These cells patrol the brain, clear waste, and support normal connections between nerve cells.
In bone, the CSF1R gene helps form and guide osteoclasts, the cells that clear away old bone. This normal bone turnover creates space for fresh bone and supports healthy bone remodeling.
What is a variant?
A genetic variant is a minor difference in the DNA sequence within a gene. These changes are common and help shape normal human diversity, including differences in appearance, metabolism, and the way the body responds to environmental influences. Many 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 significantly and can contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Changes in the CSF1R gene often alter the receptor's shape or stability, especially in its signaling region, so the cell receives a weaker message or none at all. This helps explain how CSF1R gene variants affect cell signaling: some variants partly reduce receptor activity, while more severe variants can greatly impair signaling or lead to little usable protein. In CSF1R-related leukoencephalopathy, stronger loss of function may be linked to earlier onset or broader features in some families.
How variants are linked to conditions
Pathogenic variants in the CSF1R gene are a well-established cause of CSF1R-related adult-onset leukoencephalopathy, often called ALSP. This inherited brain condition is linked to gradual changes in walking, thinking, behavior, and movement, usually starting in adulthood. More rarely, variants affecting both copies of the CSF1R gene have been associated with earlier-onset conditions that involve brain development and, in some people, bone changes.
A variant is not necessarily a diagnosis
Variants in genes are a routine part of human biology and are widely seen in the general population. Most do not have a direct effect on health and instead reflect natural human diversity. For many genes, carrying a variant associated with a condition suggests a possible link rather than a definite diagnosis, especially when several genes and environmental factors contribute. 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 CSF1R-related disease, risk is driven mainly by whether you carry a disease-causing CSF1R variant, often inherited in families. There is not yet broadly confirmed evidence that lifestyle, diet, or everyday exposures clearly increase or lower that inherited risk. Age can affect when signs begin, so monitoring and early evaluation of new neurologic symptoms can be important.
Inheritance of CSF1R variants
Most disease-causing changes in the CSF1R gene are inherited in an autosomal dominant pattern, which helps explain how CSF1R variants are inherited in families. This means a person with a disease-causing variant has one changed copy of the gene and one usual copy, and each child has a 50% chance of inheriting the changed copy. The CSF1R gene is not on a sex chromosome, so this pattern is the same for sons and daughters, and a variant can be passed down by either parent.
What does my CSF1R result mean for my family?
For CSF1R, what this means for relatives depends on which CSF1R-related condition the result is linked to. In the better-known adult-onset brain white matter condition, a changed copy can run in families, so close relatives such as a parent, brother, sister, or child may also carry the same result. CSF1R is also linked to rarer conditions that follow a different family pattern, where parents may be healthy carriers and siblings could still be affected.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a change in the CSF1R gene, doctors use genetic testing on a blood sample or saliva. CSF1R genetic testing reads the gene’s DNA code and looks for variants that may help explain symptoms or a family history. Results are interpreted alongside your medical history.
When should I consider getting a genetic test?
Consider CSF1R genetic testing if there is a family history of an inherited brain white matter condition, or if someone has unexplained changes in thinking, behavior, walking, stiffness, or tremor along with MRI changes. Testing can help confirm a CSF1R-related condition.
A genetic result is only one part of your health story
Genetic results can be informative, but the amount of information they provide varies with the condition and the specific type of variant. Over time, the body is also shaped by many other factors, including lifestyle, environment, age, and medical history. In some conditions, particularly those affected by many genes, genetics offers context rather than certainty and makes the most sense when considered with the rest of a person’s care. In other situations, a genetic result can give a clear answer. For areas like medication response, these results may also help put personal experiences in context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. This helps explain why the same drug may work well for one person, do very little for another, or cause more side effects in someone else. Part of the reason is that genes can influence how the body breaks down, moves, or responds to a medicine, which can change both treatment effect and sensitivity.
What is Pharmacogenetics?
Pharmacogenetics examines how differences in genes can affect the way people respond to medicines. It studies gene and drug patterns to help explain why the same treatment may work differently from one person to another. For many medications, genes influence either how strong the drug’s effects are or how the body handles it. This information can support treatment choices that are both better informed and more individualized. More detailed information on this topic is available in the LearnHub.
Drugs influenced by the CSF1R gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choices, so any concerns about symptoms, treatment, or medicine side effects are best discussed with your doctor.
History
Interest in the CSF1R gene grew from cancer research in the late 20th century, when scientists connected it to the viral oncogene v-fms found in a cat cancer virus. In recent decades, awareness of this gene’s role has grown as researchers recognized its place in both blood cell biology and inherited brain disease. Building on this early work, scientists showed that CSF1R was the human counterpart of c-fms, which helped clarify how certain cell growth signals are received. A major shift came in the 2010s, when pathogenic variants in the CSF1R gene were identified as a cause of a rare adult-onset condition affecting the brain’s white matter, now often grouped under ALSP. These findings reshaped diagnosis and linked older clinical descriptions to a specific inherited cause.