The FAM20C gene helps control how bones and teeth form by adding small chemical tags to proteins that guide mineral buildup. Your body relies on this gene to keep that process balanced, so pathogenic variants can cause Raine syndrome, a genetic condition that affects bone growth and the shape and strength of bones and teeth. Some people have a severe form early in life, while others have milder features such as dental changes, short stature, or bone pain.
What is a gene?
Genes are stretches of DNA that carry instructions your cells use to make molecules or direct processes in the body. Some genes hold the information needed to produce proteins, the parts of cells that do the work. Other genes mainly help regulate when certain processes happen, where they take place, and how strongly they are carried out. Taken together, genes affect how the body develops and works, and they can also influence how you respond to food, stress, or medications. You can find more detailed information about this topic in the LearnHub.
Overview
FAM20CGene function
What if the gene works
The FAM20C gene helps activate proteins that guide mineral buildup in bones and teeth. This supports normal skeletal growth and the hard outer layers of teeth.
Risk
What if the gene does not work
Variants in the FAM20C gene can affect how bones and teeth harden. More severe variants may cause Raine syndrome from birth, while milder ones can cause low phosphate, softer bones, and dental problems.
Treatment
What does that mean for your treatment
No FAM20C-specific treatment or management approach is currently established. The FAM20C gene is being studied in early-stage research on bone and tooth mineralization and phosphate balance, but this work does not yet guide routine drug choices.
Conditions associated with FAM20C
Gene function
What if the gene works
Deep inside the cell’s protein packing area, the FAM20C gene helps place small chemical tags on certain proteins before they are sent out to work. These tags help many proteins act in the right place and at the right time. Understanding FAM20C gene function helps explain how your body supports healthy bone and tooth mineralization.
The FAM20C gene adds small phosphate tags to selected proteins in the Golgi apparatus (the cell’s packaging area). This step helps those proteins mature properly and carry out their jobs after they leave the cell.
Many proteins in bone need tags added by FAM20C to guide where minerals are laid down. This supports normal bone building and helps the mineral framework form in an organized way.
In teeth, FAM20C prepares proteins that help form dentin, the hard layer under enamel. This supports normal tooth mineralization and the usual internal tooth structure.
What is a variant?
A genetic variant is a minor change in the DNA sequence within 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
Variants in the FAM20C gene can alter the protein’s shape, stability, or trafficking inside the cell, lowering its ability to add phosphate tags to other proteins. Some variants leave partial activity, while more disruptive variants can greatly reduce or stop it. This range helps explain how variants in the FAM20C gene affect protein function and why Raine syndrome may appear in milder later forms or in earlier, more severe forms.
How variants are linked to conditions
Pathogenic variants in the FAM20C gene cause Raine syndrome, a rare condition that mainly affects bone and facial development. In severe forms, babies may be born with major bone changes and breathing problems, while milder forms can be linked to short stature, dental differences, hearing loss, and developmental delay. When people read about FAM20C gene variants and Raine syndrome, it helps to know that symptoms can vary widely.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of human biology and are widely found in the general population. Most of these variants do not directly affect health and instead reflect natural human diversity. For many genes, carrying a variant associated with a condition indicates a possible link rather than a definite diagnosis, especially when several genes and environmental influences also 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 FAM20C, risk is mainly set by whether someone has disease-causing changes in both copies of the gene inherited from their parents. There is not enough evidence to say that lifestyle or environmental factors meaningfully change the chance of developing the condition. The type of gene change can affect how severe the condition is.
Inheritance of FAM20C variants
For families asking about the FAM20C inheritance pattern, FAM20C-related conditions are inherited in an autosomal recessive way. This means a child usually inherits one FAM20C gene variant from each parent, and the parents are often healthy carriers. When both parents carry a variant, each pregnancy has a 25% chance of the child having the condition, a 50% chance of being a carrier, and a 25% chance of inheriting neither variant. This pattern affects boys and girls equally.
What does my FAM20C result mean for my family?
For FAM20C, family implications are usually discussed in terms of a recessive inherited condition. Parents of an affected child are often healthy carriers, and brothers and sisters may also be carriers or, in some families, may also be affected. Close relatives may want to talk with their care team about whether family testing could help clarify carrier status.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for FAM20C variants usually uses a blood or saliva sample, and the lab reads the FAM20C gene to look for sequence changes and sometimes missing or extra pieces. This can help confirm whether a person carries two disease-causing variants or is a carrier, depending on the reason for testing.
When should I consider getting a genetic test?
Consider testing the FAM20C gene if a baby or child has a rare bone growth condition with very dense bones, unusual facial features, severe dental problems, or low phosphate causing soft bones. Testing can also help when this condition runs in the family or when a pregnancy is known to be at risk.
A genetic result is only one part of your health story
A genetic result can provide valuable insight, but how much it reveals depends on the condition and the specific type of variant involved. Over time, many factors such as lifestyle, environment, age, and medical history also influence how the body functions. For some conditions, especially those shaped 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 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. The same drug and dose may work well for one person, help less in another, or cause more side effects because the body can absorb, break down, or respond to medicines differently. These differences are common and are one reason treatment response is not always the same from person to person.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences can affect the way a person responds to medications. It studies links between genes and drugs to better explain why the same treatment can work differently from one person to another. For many medicines, genes 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 individualized. More details on this topic are available in the LearnHub.
Drugs influenced by the FAM20C gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choices, so general concerns about symptoms, side effects, or how well a treatment is working are best discussed with your doctor.
History
FAM20C entered medical genetics through studies of families affected by Raine syndrome, a rare condition affecting bone development. In the late 2000s, researchers linked pathogenic variants in the FAM20C gene to this condition, giving families and clinicians a clearer genetic explanation. Initially understood only through visible traits, later recognized as tied to a specific gene, the story of FAM20C reflects how rare conditions can open new paths in genetics. Building on this early work, scientists connected FAM20C to broader research on how bones and teeth form. Over time, descriptions became more precise. These historical steps shaped today’s understanding of FAM20C as an important gene in mineralized tissues.