The AR gene gives your cells instructions for a receptor that lets the body respond to testosterone and related hormones, which helps shape sexual development, fertility, muscle, hair growth, and prostate function. If this gene does not work properly, the body may not respond to these signals as expected, which can lead to differences in sex development, infertility, or changes in hair and body features. Some variants in the AR gene are also linked to prostate cancer behavior or to a nerve and muscle condition called Kennedy disease.
What is a gene?
A gene is a stretch of DNA that carries instructions your cells use to make molecules or regulate processes in the body. Some genes hold the information needed to produce proteins, the parts of cells that do much of the work. Other genes mostly help determine when certain processes happen, where they take place, and how strongly they are active. Together, genes affect how the body develops and functions, and they can influence how you respond to food, stress, or medications. You can find more detailed information on this topic in the LearnHub.
Overview
ARGene function
What if the gene works
The AR gene makes the androgen receptor, which lets cells respond to hormones such as testosterone. This helps guide male sexual development and supports muscle, bone, skin, and reproductive function.
Risk
What if the gene does not work
Variants in the AR gene can weaken the body's response to androgens, ranging from mild infertility to complete androgen insensitivity with differences in sex development. Certain repeat expansions in the AR gene can also cause spinal and bulbar muscular atrophy.
Treatment
What does that mean for your treatment
No AR-specific treatment or drug choice is currently established for inherited pathogenic or loss-of-function variants in the AR gene. The AR gene is also a major drug target and biomarker in prostate cancer, where treatment can include blocking androgen signaling.
Conditions associated with AR
Gene function
What if the gene works
In daily life, the AR gene helps the body respond to testosterone and related hormones called androgens. This allows many tissues to adjust growth, maintenance, and communication in a coordinated way. Its protein acts like a sensor and messenger, turning hormone signals into changes in gene activity.
The AR gene makes a receptor protein that binds androgens such as testosterone and dihydrotestosterone. Once it senses these hormones, the signal can be passed into the cell in a usable form.
After binding an androgen, the receptor moves to the cell nucleus, where DNA is stored. There, it switches specific genes on or off so cells can carry out the right hormone response.
This signaling helps reproductive tissues, muscle, bone, skin, and hair follicles respond appropriately to everyday hormone levels. It supports typical patterns of growth, upkeep, and function across these tissues.
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
How AR gene variants affect the androgen receptor depends on the type of DNA change. Some variants weaken hormone binding, disrupt folding, or stop the protein from reaching the cell nucleus, while milder loss-of-function variants may leave some signaling intact and more severe ones can greatly reduce it, often leading to earlier or more marked androgen insensitivity. A CAG repeat expansion in the AR gene changes the protein differently, making it more likely to build up inside cells, as seen in spinal and bulbar muscular atrophy.
How variants are linked to conditions
Some AR gene variants cause androgen insensitivity syndrome, including complete, partial, and mild forms, which affect sexual development in people with a 46,XY chromosome pattern. An unusually long repeated section in the AR gene causes spinal and bulbar muscular atrophy, also called Kennedy disease, which usually begins in adulthood with muscle weakness, cramping, or tremor.
A variant is not necessarily a diagnosis
Across the general population, genetic variants are common and are a normal part 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 suggests a possible link rather than a definite diagnosis, especially when several genes and environmental factors contribute. In some situations, though, a single well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For the AR gene, risk is usually driven mainly by the specific inherited change itself rather than by lifestyle. Because AR is on the X chromosome, sex and family history can strongly affect who develops related conditions and how they show up. In some AR-related conditions, the exact change can also influence age of onset or severity.
Inheritance of AR variants
Variants in the GENE gene are inherited in an autosomal recessive pattern. This means a person usually inherits one nonworking copy from each parent to have the related condition. Parents who each carry one GENE gene variant are often unaffected carriers, and with each pregnancy there is a 25% chance their child will inherit both variants, a 50% chance the child will be a carrier, and a 25% chance the child will inherit neither variant. This is the usual pattern described for GENE gene inheritance.
What does my AR result mean for my family?
A result in the {{GENE}} gene can matter for close relatives because these conditions are usually passed down through families in a recessive pattern. Parents are often healthy carriers, brothers and sisters may also have the same condition or be carriers, and other relatives may carry the change too. For family planning, the result can also be relevant for a partner, because two carriers can have a child with the condition.
Genetic information
Genetic testing
How you find out about variants
AR gene genetic testing usually uses a blood or saliva sample to read the AR gene and look for variants. Labs most often use DNA sequencing, and some also check for missing or extra pieces of the gene. Results may identify a pathogenic variant, a benign variant, or a variant of uncertain significance.
When should I consider getting a genetic test?
Consider AR genetic testing if there is a personal or family history of a condition where the body does not fully respond to male sex hormones, unexplained differences in sex development, or some types of male infertility. It may also help explain an inherited adult-onset condition with slowly worsening muscle weakness and tremor, known as Kennedy disease.
A genetic result is only one part of your health story
A genetic finding can be very informative, but how much it explains depends on the condition and on the kind of variant involved. How the body works over time is also shaped by many factors, including age, environment, lifestyle, and medical history. For some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is best understood as part of the broader picture of care. In other situations, a genetic result can 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. Small differences in genes can change how the body breaks down a drug, moves it through the body, or responds to it at its target. This helps explain why the same medication may work well for one person, have less effect in another, or cause more side effects in someone who is more sensitive to it.
What is Pharmacogenetics?
Pharmacogenetics examines how differences in genes affect the way people respond to medicines. By studying links between genes and drugs, it helps explain why the same treatment can work differently in different people. For many medicines, genes influence how much effect a drug has or how the body handles it. This information can support treatment decisions that are better informed and more individualized. More detail on this topic is available in the LearnHub.
Drugs influenced by the AR gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in routine medication prescribing, so general questions about medicines or side effects are best discussed with your doctor. In prostate cancer, changes in the AR gene found in the tumor can affect how well some hormone-blocking treatments work, so this may be worth discussing with your cancer team.
History
The AR gene has a long and important place in medical history because it helped explain why some inherited sex development patterns and hormone related conditions run in families. Throughout history, people have described features that hinted at this gene. In the 20th century, doctors linked certain family patterns to what was then called testicular feminization, a historical term now replaced by androgen insensitivity syndrome. Building on this early work, researchers identified the AR gene in the late 1980s, which clarified the cause of several inherited conditions and opened a new chapter in hormone research. AR also became central to prostate cancer research as scientists learned that changes in AR signaling can shape how some cancers grow and respond to treatment. Over time, the AR gene’s history has connected genetics, endocrinology, and cancer care in a lasting way.