AIS is a genetic disorder that affects the development of a person’s reproductive and sexual characteristics because their bodies don't respond to testosterone properly.
AIS is a condition linked to genes on the X chromosome. To find out if someone has AIS, they need a special genetic test, usually from a genetic specialist. Regardless of whether someone has a formal diagnosis or not, treatment involves making sure the body gets the right hormones and adjusting the doses to get the best response.
What Is AIS?
AIS is a genetic condition in which an individual is partially or completely insensitive to androgens, including testosterone. This insensitivity disrupts the normal process of sexual development, leading to the development of female or ambiguous external genitalia and secondary sexual characteristics.
Types of AIS
There are three main types of AIS
- Complete Androgen Insensitivity Syndrome (CAIS): CAIS is a complete insensitivity to androgens. People with CAIS usually develop female external traits. CAIS is often not diagnosed until puberty when menstruation does not occur.
- Partial Androgen Insensitivity Syndrome (PAIS): PAIS is partial sensitivity to androgens, resulting in a range of presentations, including ambiguous genitalia or male external traits with underdeveloped secondary sexual characteristics. The genitals may look small or underdeveloped.
- Mild Androgen Insensitivity Syndrome (MAIS): MAIS is the mildest form of the condition. XY individuals with MAIS have typically male external genitalia and typical male secondary sexual characteristics, but they may have reduced sensitivity to testosterone.
Causes
Androgen insensitivity syndrome is an inherited condition. AIS is caused by mutations in the Androgen Receptor (AR) gene located on the X chromosome. These mutations affect the function of the androgen receptor, causing reduced or no response to testosterone.
This prevents the foetus from responding to the male hormone, interfering with the development of the internal and external sex organs and preventing all or some of the masculinising effects of testosterone.
XX and XY Chromosomes
Chromosomes carry genetic information that control various traits, including an individual’s sex. Typically, people with two X chromosomes (XX) experience typical female development, and those with one X and one Y chromosome (XY) have typical male development.
In AIS, individuals with XY chromosomes may exhibit external genitalia that differ from what is typically associated with their chromosomes. This can result in female-looking or ambiguous genitalia.
People with XX chromosomes who identify as male and have the AIS gene on one or more of their X chromosomes may experience variations in androgen sensitivity, though the effects of such interactions remain an area of limited research.
For someone who is XX to have complete androgen insensitivity, they would have to have the gene on both of their X chromosomes, implying that their genetic father was themselves someone with AIS.
Diagnosis
A physical examination of an XY person may reveal atypical genitalia, which can prompt further investigation. Genetic testing can confirm the presence of AR gene mutations. Tests used to confirm this condition include blood tests to check hormone levels, genetic testing and pelvic ultrasound to look at the reproductive organs.
Gender Identity
For those with Androgen Insensitivity Syndrome (AIS), gender identity may not necessarily align with their external appearance. Individuals with AIS, like everyone else, have the right to explore, express, and identify with the gender that resonates most with their inner sense of self.
Management
Management may include regular check-ups to monitor any potential health concerns, such as the risk of testicular cancer in individuals with retained testes. Healthcare providers and psychologists can offer support to address the emotional and psychological aspects of living with AIS, including discussions about body image, gender identity, and sexual health.
The management of AIS should prioritise the individual’s wellbeing, making sure they have access to the information and resources they need to make informed decisions about their health and life journey.
Hormone Therapy for Those Identifying as Male
People with Androgen Insensitivity Syndrome (AIS) who identify as male, may need higher doses or different preparations to can help if development is slow.
Living with AIS
Living with AIS can pose unique challenges. Individuals with AIS may face issues related to gender identity, body image, and sexual health. Supportive healthcare professionals, psychologists, and peer support networks can help navigate these challenges and make informed decisions about health and wellbeing.