Overview
Androgen insensitivity syndrome (AIS) is a rare genetic condition where a person who is genetically male (XY chromosomes) is resistant to male sex hormones (androgens). As a result, they may have the physical traits of a female or both male and female characteristics. AIS occurs in varying degrees, ranging from complete to partial forms.
Symptoms
Complete AIS: female external genitalia, no uterus, undescended testes Partial AIS: ambiguous genitalia (features of both male and female) Lack of menstruation during puberty (primary amenorrhea) Little or no body hair or underarm hair Normal breast development at puberty
Causes
Mutations in the AR (androgen receptor) gene Inherited in an X-linked recessive pattern Results in cells being unable to respond properly to androgens
Diagnosis
Physical examination of genitalia Karyotyping (chromosome analysis) to determine XY pattern Hormone tests showing normal or high levels of androgens Genetic testing for AR gene mutations Imaging (ultrasound or MRI) to look for internal reproductive structures
Treatment
Psychological support and counseling Gonadectomy (removal of undescended testes) after puberty to reduce cancer risk Hormone replacement therapy after gonad removal Surgical procedures for gender-affirming care if desired Fertility counseling (individuals with AIS are infertile)
Complications
Increased risk of testicular cancer (in undescended testes) Psychological and social challenges Infertility
Prevention
No prevention for the genetic mutation Genetic counseling for families with AIS history Early diagnosis to manage health and psychosocial outcomes