Physical diagnosis
Partial androgen insensitivity syndrome (PAIS) can usually be diagnosed at birth, as the genitals are visibly different.
A physical diagnosis of complete androgen insensitivity syndrome (CAIS) is more difficult. Many children are diagnosed early in life when their testes cause hernias (soft bulges or swellings under the skin). When the hernias are operated on, the testes are discovered and CAIS is diagnosed.
If a girl with CAIS does not develop a hernia, the condition may not be diagnosed until puberty, when her periods do not start and a lack of pubic and underarm hair becomes apparent.
Blood test
Androgen insensitivity syndrome (AIS) can be confirmed using blood tests, which measure the level of hormones in the blood and reveal the altered X chromosome.
Ultrasound scan
An ultrasound scan (a way of producing pictures of inside the body using sound waves) can be used to confirm the absence of female internal reproductive organs when AIS is suspected.
Before birth
If the alteration (mutation) in the gene that produces the androgen receptors has been identified, AIS can be diagnosed after the 11th week of pregnancy. This is done either by chorionic villus sampling (CVS), which involves taking cells from the placenta (or afterbirth), or from the 15th week of pregnancy by amniocentesis (taking fluid from around the baby).
The decision to have a test in a pregnancy may be complex and require careful genetic counselling. Because the condition is rare, unborn babies are not routinely tested for AIS unless there is a family history of the condition.
