The HAX1 gene helps certain cells stay healthy and survive, especially infection-fighting white blood cells called neutrophils and some nerve cells. The protein made by this gene helps your cells manage stress and avoid breaking down too early. If the HAX1 gene does not work properly, a person may be born with very low neutrophil levels, which can lead to repeated bacterial infections. Some people with more disruptive variants also have developmental delay, seizures, or movement problems.
What is a gene?
A gene is a stretch of DNA that provides information your cells use to make molecules or direct processes in the body. Some genes hold the instructions for producing proteins, the active parts of cells. Others mainly regulate when certain processes take place, where they occur, and how strongly they run. Together, genes affect how the body develops and functions, and they can also shape how you respond to food, stress, or medicines. For a more detailed look at this topic, you can learn more in the LearnHub.
Overview
HAX1Gene function
What if the gene works
The HAX1 gene helps cells stay alive and keep their internal framework organized. Its protein supports energy production, calcium balance, and movement inside cells, especially in blood-forming cells and nerve cells.
Risk
What if the gene does not work
Variants in the HAX1 gene most often cause severe congenital neutropenia, with very low infection-fighting white blood cells and repeated bacterial infections from infancy. Milder or more severe variants may change whether developmental delay or seizures also appear.
Treatment
What does that mean for your treatment
No HAX1-specific treatment or drug choice approach is currently established. The HAX1 gene is being studied as a cancer biomarker and possible drug target, but this has not yet changed routine care.
Conditions associated with HAX1
Gene function
What if the gene works
HAX1 helps cells stay steady during everyday stress. Its protein is active in areas that support energy balance, calcium control, and the cell’s internal framework. Understanding how the HAX1 gene helps cells survive and move can make its role in the body easier to picture.
HAX1 helps cells regulate the built in process of programmed cell death, which is the body’s normal way of removing cells. This supports cell survival during routine stress and everyday wear.
Its protein helps keep mitochondria, the parts of cells that make energy, stable. This supports steady energy use and helps cells manage calcium, a mineral signal used for many cell activities.
HAX1 works with proteins that organize the cell’s inner framework. This helps cells keep their shape, attach where needed, and move in a coordinated way during normal tissue activity.
What is a variant?
A genetic variant is a minor difference in the DNA sequence within a gene. These differences are common and help shape normal variation among people, including traits such as appearance, metabolism, and the body’s response to environmental factors. Many variants do not produce any noticeable effects and are simply part of natural genetic diversity. At times, though, a variant can change how a gene works to a greater degree and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
HAX1 gene variants often reduce how much HAX1 protein a cell can make or leave it too short and unstable to support cell survival, especially in infection-fighting white blood cells. Milder variants may preserve some activity, while more disruptive variants can nearly eliminate it. This summary of how HAX1 gene variants affect protein function helps explain why some people have isolated severe congenital neutropenia, while changes that disrupt more than one HAX1 form can also be linked to neurologic features.
How variants are linked to conditions
Pathogenic variants in the HAX1 gene are most clearly linked to severe congenital neutropenia, also called severe congenital neutropenia type 3 or HAX1-related congenital neutropenia. This rare inherited condition usually starts in infancy, with very low neutrophil counts and repeated bacterial infections. Some people with HAX1 gene variants linked to severe congenital neutropenia also have developmental delay, seizures, or other neurologic features, depending on the specific variant.
A variant is not necessarily a diagnosis
Genetic variants are a normal part of being human and are common throughout the general population. Most do not have a direct effect on health and simply 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 play a role. There are some cases, however, where a single, well-characterized variant in a specific gene can by itself confirm a diagnosis.
Are there things that can increase or change my risk?
There is not broadly confirmed evidence that lifestyle, diet, or everyday exposures clearly increase or reduce health risks related to the HAX1 gene. For inherited HAX1-related conditions, risk is mainly shaped by the gene change itself and family inheritance, so personal guidance from a doctor or genetic counselor can help put that risk in context.
Inheritance of HAX1 variants
HAX1-related conditions are inherited in an autosomal recessive pattern, which explains how HAX1 variants are inherited in families. This means a child usually inherits one altered copy of the HAX1 gene from each parent. Parents who each carry one variant are often unaffected, and with each pregnancy there is a 25% chance of having a child with the condition, a 50% chance of having a child who is a carrier, and a 25% chance of having a child who inherits neither variant. Because the HAX1 gene is on chromosome 1, it can be passed on by either parent to sons or daughters.
What does my HAX1 result mean for my family?
For HAX1, family impact is usually discussed in a recessive pattern. This often means parents are healthy carriers, brothers or sisters may also be affected or may be carriers, and other close relatives could carry the same gene change. Children of someone with a HAX1-related condition will usually be carriers unless the other parent also carries a HAX1 change.
Genetic information
Genetic testing
How you find out about variants
To learn how HAX1 genetic testing works, a lab uses a blood or saliva sample to read the HAX1 gene and look for variants. Testing may look only at this gene or include it in a larger panel, and results can show a disease-causing variant, no relevant variant, or a variant with uncertain meaning.
When should I consider getting a genetic test?
Genetic testing for the HAX1 gene may be considered when a baby or child has repeated serious infections, mouth sores, fevers, and blood tests showing very low infection-fighting white blood cells. It can also help when severe low white blood cell counts run in the family or a child already has a diagnosis of severe congenital neutropenia.
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 type of variant involved. Many factors, including lifestyle, environment, age, and medical history, influence how the body works over time. For some conditions, especially those shaped by many genes, genetic information provides context rather than certainty and is most useful when considered alongside other parts of care. In other situations, a genetic result may offer a clear answer. In areas like medication response, genetic results can help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. This helps explain why the same treatment works well for one person, seems less effective for another, or causes more side effects in someone else. Differences in how the body absorbs, breaks down, transports, or responds to a drug are common, and these differences can shape both benefit and sensitivity.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences affect the way people respond to medicines. It looks at the connection between genes and drugs to better understand why the same treatment may work differently from one person to another. For many medications, genes influence both how strongly a drug works and how the body handles it. This information can support treatment decisions that are more informed and more personalized. You can read more about this topic in the LearnHub.
Drugs influenced by the HAX1 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in predicting medication response, so questions about symptoms, side effects, or medicines are best discussed with your doctor.
History
HAX1 entered medical genetics through work on severe congenital neutropenia, a rare inherited condition first described decades earlier in families from northern Sweden and often called Kostmann disease. In the late 1990s, researchers identified HAX1 as a new human gene during studies of cell proteins. Building on this early work, scientists later showed that pathogenic variants in the HAX1 gene explain some cases of Kostmann disease, helping connect a long recognized clinical pattern to a specific genetic cause. This finding clarified why some affected children had very low neutrophil counts from infancy. Over time, descriptions became more precise as different HAX1 variants were linked with somewhat different features. These studies helped place the HAX1 gene within the broader history of rare blood and immune conditions.