The ATXN8 gene is active in the brain and is involved in the function of nerve cells that help control balance and coordinated movement. When this gene region carries a large repeat expansion, it can interfere with those nerve cells and is linked to spinocerebellar ataxia type 8, which may cause unsteady walking, slurred speech, and problems with fine movements. Symptoms often appear gradually and can vary a lot from one person to another, even within the same family.
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 provide the directions for making proteins, which are the working parts of cells. Others mainly help determine when certain processes happen, where they take place, and how strongly they run. Taken together, genes affect how the body develops and works, and they can also influence how you respond to food, stress, or medications. For a more detailed look at this topic, you can read more in the LearnHub.
Overview
ATXN8Gene function
What if the gene works
The ATXN8 gene helps make ataxin-8, a protein found in the brain and other tissues. It is thought to support normal nerve cell activity.
Risk
What if the gene does not work
Changes in the ATXN8 gene are linked to spinocerebellar ataxia type 8, which can cause unsteady walking, poor coordination, and slurred speech. Milder to more severe variants may influence whether symptoms appear, when they start, and how movement is affected.
Treatment
What does that mean for your treatment
No ATXN8-specific treatment or drug selection approach is currently established in clinical guidelines. Care is based on symptoms, and the ATXN8 gene is being studied in repeat expansion ataxias as a possible target for RNA based therapies, but this remains investigational.
Conditions associated with ATXN8
Gene function
What if the gene works
The ATXN8 gene is most relevant in brain cells, especially in areas that help with balance and coordinated movement. In simple terms, ATXN8 gene function centers on giving cells instructions to make ataxin-8 for routine nerve cell activity.
The ATXN8 gene provides the code for making the ataxin-8 protein. When cells use that code normally, they add this protein to everyday work inside nerve cells.
Ataxin-8 is made most strongly in brain tissue linked with balance and coordinated movement. In those areas, it forms part of normal day to day nerve cell activity.
What is a variant?
A genetic variant is a small difference in the DNA sequence of a gene. These changes are common and are part of normal human diversity, including differences in appearance, metabolism, or how the body responds to environmental influences. Many variants have no noticeable effect and simply represent natural genetic variation. In some cases, however, a variant can change the function of a gene more markedly and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Most important variants in the ATXN8 gene are expanded DNA repeats rather than small spelling changes. In an ATXN8 gene repeat expansion, the unusually long repeat can produce RNA and protein products that are harder for cells to process, which may disturb nerve cell function and lead to spinocerebellar ataxia type 8. Shorter expansions may have less effect, while larger expansions often disrupt cell function more and can be linked to earlier or more marked symptoms, although the pattern varies.
How variants are linked to conditions
Variants in the ATXN8 gene are most clearly linked to spinocerebellar ataxia type 8, an inherited condition that can affect balance, walking, speech, and coordination. In the ATXN8 gene and spinocerebellar ataxia type 8 association, the usual finding is a repeat expansion rather than a small DNA change. Some people with this expansion develop symptoms while others do not, so the result needs careful clinical interpretation.
A variant is not necessarily a diagnosis
Genetic variants are common across the general population and are a normal feature of human biology. Most do not directly affect health and simply contribute to natural human diversity. For many genes, having a variant associated with a condition points to a possible link rather than a definite diagnosis, particularly when several genes and environmental influences play a role. In other situations, though, one well characterized variant in a particular gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For ATXN8, risk is mainly shaped by whether someone has a repeat expansion in this gene, which can run in families. There is not yet broadly confirmed evidence that lifestyle or everyday exposures clearly increase or reduce the chance of developing symptoms related to ATXN8.
Inheritance of ATXN8 variants
ATXN8-related changes are usually passed down in an autosomal dominant pattern, which means a parent carrying the variant can pass it to each child with a 50% chance. In practical terms, how ATXN8 gene variants are inherited is the same for sons and daughters, because the gene is on chromosome 13, not a sex chromosome. Some people who inherit an ATXN8 variant develop symptoms, while others may never do so, so the pattern of inheritance is clearer than the pattern of symptoms.
What does my ATXN8 result mean for my family?
A harmful change in the ATXN8 gene is usually passed through families in a dominant pattern, so close relatives such as parents, brothers, sisters, and children may also carry it. That means family members may want to learn whether the same change is present, especially if there is a history of balance problems, slurred speech, or trouble with coordination. In some families, people with the same ATXN8 change can be affected very differently, and some may have few or no symptoms.
Genetic information
Genetic testing
How you find out about variants
ATXN8 genetic testing usually uses a blood or saliva sample to check for a repeat expansion, a stretch of DNA that is longer than expected, in the ATXN8 gene. The lab measures the size of this repeated section to see whether a condition linked variant is present.
When should I consider getting a genetic test?
A genetic test for ATXN8 may be worth considering if you or close relatives have unexplained balance and coordination problems, trouble walking, or slurred speech, especially when these symptoms seem to run in the family. Testing is usually considered as part of an evaluation for inherited ataxia, a condition that affects movement and balance.
A genetic result is only one part of your health story
A genetic result can be helpful, but how much it reveals varies by the condition and the type of variant involved. Age, lifestyle, environment, and medical history, among other factors, also shape how the body functions over time. In some conditions, especially those influenced by many genes, genetic information offers context rather than certainty and is most useful when viewed alongside other parts of care. In other situations, a genetic result may give a clear answer. In areas such as medication response, genetic results can also help put individual experiences into perspective.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. This is one reason the same medication may work well for one person, have less effect in another, or cause more side effects in someone else. Small differences in how the body breaks down, moves, or responds to a drug are common, and they can influence how effective or how well tolerated a treatment is.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences affect a person’s response to medications. It studies links between genes and drugs to help explain why the same treatment can work differently from one person to another. For many medicines, genes influence both how the body processes a drug and how strong its effects are. This information can support more informed and more individualized treatment decisions. More on this topic is available in the LearnHub.
Drugs influenced by the ATXN8 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choice or response, so questions about medicines, side effects, or new symptoms are best discussed with your doctor.
History
The ATXN8 gene entered the medical literature in the late 1990s, when researchers linked an unusual repeat expansion in this region to spinocerebellar ataxia type 8, or SCA8. Early reports drew attention because the finding did not fit neatly with the patterns already known from other inherited ataxias. From these first observations, research expanded steadily. Scientists later showed that this stretch of DNA was more complex than first thought, with activity on both sides of the same region and a neighboring gene, ATXN8OS, also becoming part of the story. That work made the ATXN8 gene an important chapter in the history of repeat expansion diseases and changed how some neurologic conditions were studied.