Androgen insensitivity syndrome
Overview
Androgen insensitivity syndrome (AIS) affects the development of a person's genitals and reproductive organs.
Causes
AIS is caused by a genetic alteration that is passed along the female line to the child. Although people with AIS have XY (usual male pattern) chromosomes, the body does not respond to testosterone (the sex hormone) fully or at all. This prevents the sex development of a typical male. A penis does not form or is underdeveloped. This means the child's genitals may develop as female, or are underdeveloped as male. The child may have fully or partiallyundescended testicles. But there will be no womb or ovaries. Women who carry the genetic alteration will not have AIS themselves, but there's a 1 in 4 chance each child they have will be born with AIS. Read more about thecauses of AIS.