Androgen insensitivity syndrome is a condition that affects sexual development before birth and during puberty. People with this condition are genetically male, with one X chromosome and one Y chromosome in each cell. Because their bodies are unable to respond to certain male sex hormones (called androgens), they may have mostly female sex characteristics or signs of both male and female sexual development. There are three types of androgen insensitivity syndrome which vary in severity. There are different management options, so talk to your doctor about the best care plan if you or your child has been diagnosed with androgen insensitivity syndrome. For more information about the different types, please visit: mild androgen insensitivity syndrome; partial androgen insensitivity syndrome; or complete androgen insensitivity syndrome.
Androgen insensitivity syndrome is caused by mutations in the AR gene on the X chromosome. It is inherited (runs in families) as an X-linked recessive trait. Normally, we have two copies of every gene, one on a chromosome inherited from each of our birth parents. Recessive means that both copies of the gene must have the change which causes the condition. However, the sex chromosomes are different. A male has one X and one Y chromosome, whereas a female has two X chromosomes. So a male only has one copy of a gene on the X chromosome, and if this one copy has the mutation, he will have androgen insensitivity syndrome. Talk with a genetic counselor if you or a family member has been diagnosed with androgen insensitivity syndrome.