The JAGN1 gene helps the bone marrow make healthy neutrophils, which are white blood cells that fight bacteria and fungi. This gene plays an important role in helping these cells mature and work properly. If both copies of the gene do not work as they should, a person can have very low neutrophil levels and repeated infections from early life, often affecting the mouth, skin, lungs, or blood. Pathogenic variants in the JAGN1 gene are linked to a rare inherited condition called severe congenital neutropenia.
What is a gene?
Genes are sections of DNA that carry instructions your cells use to make molecules or regulate processes in the body. Some provide the directions for producing proteins, which are the parts of cells that do the work. Others are mainly involved in controlling when certain processes happen, where they happen, and how active they are. In combination, genes affect how the body develops and functions, and they can also shape how you respond to food, stress, and medications. For a deeper look at this topic, you can learn more in the LearnHub.
Overview
JAGN1Gene function
What if the gene works
The JAGN1 gene helps bone marrow make healthy neutrophils, a type of white blood cell that fights infection. It also supports protein handling inside cells, which helps these immune cells mature and work properly.
Risk
What if the gene does not work
Variants in the JAGN1 gene most often cause severe congenital neutropenia, with too few infection-fighting white blood cells and repeated bacterial or fungal infections. Milder and more severe variants can affect when symptoms begin and how marked they are.
Treatment
What does that mean for your treatment
No JAGN1-specific treatment or drug selection approach is currently established.
Conditions associated with JAGN1
Gene function
What if the gene works
Inside your cells, the JAGN1 gene helps manage early protein handling. Across many tissues, this gene contributes to steady, routine cell activity by supporting the endoplasmic reticulum, the cell compartment that folds and prepares proteins. This is a core part of how the JAGN1 gene helps proteins fold and move through the cell.
The JAGN1 gene helps the endoplasmic reticulum, the part of the cell that folds and prepares proteins, work smoothly. This gives newly made proteins time to be shaped, checked, and readied for the next step.
One of its main roles is to support glycosylation (adding small sugar chains to proteins). These sugar tags help many proteins fold properly, stay stable, and reach the right place.
The JAGN1 gene also supports the movement of proteins through the cell’s internal shipping route. In this way, proteins can leave the endoplasmic reticulum and continue toward where they are needed.
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, or the way the body responds to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. Sometimes, however, a variant changes how a gene functions more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
JAGN1 gene variants usually reduce how much JAGN1 protein a cell can make or change its shape so it cannot stay in the endoplasmic reticulum, the cell’s protein processing area. This can disrupt protein folding and the development of neutrophils, a type of infection fighting white blood cell. Milder variants may leave some activity, while more disruptive variants can leave little or none and are often linked to earlier and more pronounced severe congenital neutropenia.
How variants are linked to conditions
Pathogenic variants in the JAGN1 gene cause severe congenital neutropenia, often called severe congenital neutropenia type 6, a condition marked by very low neutrophil counts and repeated bacterial or fungal infections from early life. These JAGN1 gene variants linked to severe congenital neutropenia can also be associated with mouth sores, gum disease, skin infections, and pneumonia. Finding disease-causing variants in both copies of the JAGN1 gene can confirm the diagnosis in the right clinical setting.
A variant is not necessarily a diagnosis
Genetic variants are a common, normal feature of human biology. Most do not directly affect health and instead reflect natural differences among people. For many genes, having a variant associated with a condition points to a possible link rather than a certain diagnosis, particularly when more than one gene and environmental influences play a role. In some situations, though, one well understood variant in a particular gene is enough to establish the diagnosis.
Are there things that can increase or change my risk?
For JAGN1, the main risk is inherited: a child is affected when they receive a changed copy from both parents, so risk is higher in families where both parents carry the variant, including some related parents. Once those two changed copies are present, lifestyle does not meaningfully change the chance of the condition, so care focuses on early monitoring and preventing infections.
Inheritance of JAGN1 variants
JAGN1-related conditions are inherited in an autosomal recessive pattern. This means a child usually inherits one variant in the JAGN1 gene from each parent, and both parents are often healthy carriers. When both parents carry a variant, each pregnancy has a 25% chance of the child inheriting both changed copies, a 50% chance of being a carrier, and a 25% chance of inheriting neither variant. In practical terms, how JAGN1 gene variants are inherited usually depends on both parents passing on a changed copy.
What does my JAGN1 result mean for my family?
Changes in the JAGN1 gene are linked to an inherited condition that usually runs in families in a recessive pattern. This often means parents are healthy carriers, and brothers or sisters may also be affected or may be carriers. Other close relatives, such as future children of siblings, could also be more likely to carry the gene change in the family.
Genetic information
Genetic testing
How you find out about variants
JAGN1 genetic testing for inherited neutropenia uses a blood or saliva sample to read the JAGN1 gene and look for variants. A lab usually sequences this gene as part of a neutropenia panel or a broader inherited immune condition test. Results can show whether a pathogenic variant helps confirm the diagnosis.
When should I consider getting a genetic test?
Consider testing for the JAGN1 gene if someone has repeated serious infections and persistently very low levels of infection-fighting white blood cells, especially starting in infancy or early childhood. Testing can also help when this pattern runs in the family.
A genetic result is only one part of your health story
A genetic finding can provide useful insight, but how much it explains varies based on the condition and the specific type of variant. Many other factors, including lifestyle, environment, age, and medical history, also influence how the body functions over time. In some conditions, especially those shaped 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 can offer a clear answer. In areas like medication response, these results can also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body handles medicines, so the same treatment may work a little differently from one person to another. Some people break down a drug more slowly or more quickly, while others are more or less sensitive to its effects. This can influence how well a medicine works and the chance of side effects.
What is Pharmacogenetics?
Pharmacogenetics examines how differences in genes can shape a person’s response to medications. It focuses on gene and drug patterns to better explain why the same treatment may work differently from one person to another. For many medications, genes can affect how the body processes a drug or how strong its effects are. This information can support more informed, more individualized treatment decisions. More on this topic is available in the LearnHub.
Drugs influenced by the JAGN1 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in predicting how medicines will work, so general questions about treatment, side effects, or other health concerns are best discussed with your doctor.