The ARL6 gene gives cells instructions for a protein that helps tiny cell projections called cilia move other proteins to the right place. This gene plays an important role in how cells sense signals and support normal development. If the ARL6 gene does not work properly, cilia may not work as they should, which can cause Bardet-Biedl syndrome. People with this condition may develop gradual vision loss, weight gain, extra fingers or toes, and kidney or learning problems.
What is a gene?
Genes are stretches of DNA that give your cells instructions to make molecules or regulate activities in the body. Some genes provide the code for proteins, the parts of cells that do much of the work. Other genes are used mainly to guide when certain processes happen, where they take place, and how strongly they operate. Together, genes affect how the body develops and functions, and they can also shape how you respond to food, stress, and medications. You can find more detailed information on this topic in the LearnHub.
Overview
ARL6Gene function
What if the gene works
The ARL6 gene helps cells move key proteins in and out of cilia, tiny structures that act like cell antennae. This supports signals important for vision, kidney function, and early development.
Risk
What if the gene does not work
Pathogenic variants in the ARL6 gene can cause Bardet-Biedl syndrome, often affecting vision, body weight, kidney function, and sometimes finger or toe development. Milder and more severe variants can influence which features appear and how strongly they affect daily life.
Treatment
What does that mean for your treatment
For people with pathogenic variants in the ARL6 gene causing Bardet-Biedl syndrome, setmelanotide can be part of treatment for persistent hunger and obesity. ARL6 does not guide a unique drug choice beyond this, and care is otherwise tailored to the person’s symptoms rather than to the specific BBS gene.
Conditions associated with ARL6
Gene function
What if the gene works
Inside many cells, the ARL6 gene helps manage activity at the primary cilium, a tiny antenna-like structure that senses outside signals. Its protein acts like a switch, turning on steps that guide key proteins to the right place. Understanding how the ARL6 gene helps primary cilia work makes it easier to see how cells coordinate everyday signaling.
The ARL6 gene helps direct certain proteins to and from the primary cilium. This keeps the cilium supplied with the parts it needs to sense and relay signals.
Its protein works as a small switch that starts cilia transport at the right time. When active, it helps gather transport helpers at the ciliary membrane, the border around the cilium.
By organizing protein movement, this gene supports orderly cell signaling through the primary cilium. That helps cells respond in a more controlled way to growth and development cues.
What is a variant?
A genetic variant is a slight difference in the DNA sequence within a gene. These differences are common and help shape normal human diversity, including variations in appearance, metabolism, and the way the body responds to environmental influences. Many variants do not cause any noticeable changes and are simply part of natural genetic variation. Sometimes, though, a variant can change how a gene works more significantly and may contribute to, or directly cause, a genetic condition.
Genetic variants
What if the gene does not work
Variants in the ARL6 gene can alter the protein’s shape, stability, or ability to bind GTP (a switch molecule), weakening its interaction with the BBSome (a protein group) and disrupting cilia signaling. Milder missense variants may leave some activity, while more severe truncating or splice variants can reduce or eliminate function. This helps explain how ARL6 gene variants affect protein function and why Bardet-Biedl syndrome from ARL6 can vary in which features appear and how early they start.
How variants are linked to conditions
Pathogenic variants in the ARL6 gene are a well established cause of Bardet-Biedl syndrome, usually when both copies of the gene are affected. ARL6 gene variants linked to Bardet-Biedl syndrome can be associated with vision loss, weight gain, extra fingers or toes, kidney problems, and learning or development differences. This is the main confirmed condition associated with this gene.
A variant is not necessarily a diagnosis
Genetic variants are a routine feature of human biology and occur widely across the population. Most do not directly affect health and instead represent normal human variation. For many genes, having a variant associated with a condition points to a potential link rather than a confirmed diagnosis, particularly when several genes and environmental influences also play a role. In other situations, though, one well understood variant in a particular gene is enough to establish a diagnosis.
Are there things that can increase or change my risk?
For ARL6, risk is mainly changed by inheritance rather than lifestyle. A child’s chance of having an ARL6-related condition is higher when both biological parents carry a harmful ARL6 change, especially in families with a known history of the condition.
Inheritance of ARL6 variants
Variants in the ARL6 gene are inherited in an autosomal recessive pattern, which is the established inheritance pattern for ARL6-related Bardet-Biedl syndrome. This means a child usually inherits one altered copy from each parent, and the parents are typically healthy carriers. When both parents carry an ARL6 gene variant, each pregnancy has a 25% chance of resulting in an affected child, a 50% chance of a child who is a carrier, and a 25% chance of a child with two working copies. In practical terms, how ARL6 gene variants are inherited depends on both parents passing on the variant.
What does my ARL6 result mean for my family?
For ARL6, family implications are usually discussed in the setting of Bardet-Biedl syndrome, which is typically passed down in a recessive pattern. This often means parents are healthy carriers, brothers and sisters may also be affected or may be carriers, and other relatives could carry the same gene change without knowing it. Family members, especially siblings and relatives planning children, may want to discuss whether testing would be useful for them.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a variant in the ARL6 gene, doctors use genetic testing for ARL6 variants on a blood or saliva sample. A lab reads the gene’s DNA sequence and compares it with the usual sequence, which can identify a pathogenic variant, a benign variant, or a result that remains uncertain.
When should I consider getting a genetic test?
If you or your child has signs of Bardet-Biedl syndrome, such as worsening vision, extra fingers or toes, weight gain from early childhood, or kidney problems, testing the ARL6 gene may help confirm the cause. Testing can also be useful if this condition runs in your family or a relative has a known ARL6 variant.
A genetic result is only one part of your health story
Genetic results can provide useful insight, although how much they reveal varies with the condition and the kind of variant present. Over time, many factors shape how the body works, including lifestyle, environment, age, and medical history. For some conditions, especially those influenced by many genes, genetic information offers context rather than certainty and is most helpful when considered alongside other parts of care. In other situations, a genetic result may give a clear answer. In areas like medication response, genetic results can also help place individual experiences in context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Two people can take the same treatment, yet one may get the expected benefit while the other may have less effect or be more likely to notice side effects. This happens in part because inherited differences can change how the body breaks down, moves, or responds to a drug, and these differences are common.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences can affect the way a person responds to medication. It focuses on links between genes and drugs to better explain why the same treatment may work differently from one person to another. With many medicines, genes influence either how strongly a drug works or how the body handles it. This information can support treatment decisions that are both better informed and more individualized. You can read more about this topic in the LearnHub.
Drugs influenced by the ARL6 gene
When should I seek medical advice?
There is not currently a broadly confirmed role for this gene in guiding medication response, so any concerns about medicines, side effects, or your overall health are best discussed with your doctor.
History
Bardet-Biedl syndrome had been recognized clinically for many years before one of its genetic causes was linked to the ARL6 gene. In 2004, researchers identified variants in the ARL6 gene as the cause of a form of Bardet-Biedl syndrome, often called BBS3. From these first observations, research expanded steadily. This discovery helped confirm that Bardet-Biedl syndrome can result from changes in several different genes rather than a single shared cause. Later work placed the ARL6 gene more clearly within the growing group of Bardet-Biedl syndrome genes and supported its inclusion in modern genetic testing panels.