Androgen Insensitivity Syndrome in Genotypic Male
Overview
Plain-Language Overview
Androgen Insensitivity Syndrome (AIS) is a condition that affects people who are genetically male, meaning they have one X and one Y chromosome. It involves the body's inability to respond properly to male hormones called androgens, which are important for male sexual development. Because the body cannot use these hormones effectively, individuals with AIS may have female or ambiguous external genitalia despite having male chromosomes. This condition primarily affects the reproductive system and can influence physical development during puberty. People with AIS often have normal female external features but do not have a uterus or ovaries. The condition is caused by changes in the androgen receptor gene, which prevents cells from responding to testosterone and other androgens. AIS can impact fertility and sexual development but does not affect intelligence or other body systems.
Clinical Definition
Androgen Insensitivity Syndrome (AIS) is a genetic disorder characterized by a complete or partial inability of target tissues to respond to androgens due to mutations in the androgen receptor (AR) gene. It occurs in individuals with a 46,XY karyotype who produce normal or elevated levels of testosterone and dihydrotestosterone but exhibit varying degrees of undervirilization. The core pathology is androgen receptor dysfunction, leading to impaired masculinization of the external genitalia and secondary sexual characteristics. Clinically, AIS presents as a spectrum from complete AIS, with female external genitalia and absent Müllerian structures due to normal anti-Müllerian hormone function, to partial AIS with ambiguous genitalia. The condition is significant because it causes disorders of sex development (DSD) and challenges in gender assignment and management. Diagnosis often involves hormonal assays, genetic testing, and imaging to assess internal reproductive anatomy.