Partial androgen insensitivity syndrome (PAIS) can usually be diagnosed at birth because the genitals are visibly different. Complete androgen insensitivity syndrome (CAIS) is often not diagnosed at birth and is recognised later.
Many children with CAIS are diagnosed early in life when their testes cause hernias.
A hernia is where an internal part of the body, such as an organ, pushes through a weakness in the muscle or surrounding tissue wall. When the hernias are operated on, the testes are discovered coincidentally 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. Breast development will be normal in these girls as the high testosterone level is converted to oestrogen.
Tests and scans
If androgen insensitivity syndrome is suspected, blood tests can be used to measure the person's sex hormone levels.
An ultrasound scan can also be carried out to confirm the absence of female internal reproductive organs. Ultrasound scans use high frequency sound waves to create images of the inside of the body.
Unborn babies are not routinely tested for AIS because the condition is very rare. Pre-natal tests are often used in cases where there is a known family history of the condition.
It can sometimes be difficult to decide whether or not to have certain tests during pregnancy and in some cases genetic counselling may be necessary.
If the alteration (mutation) in the gene that produces the androgen receptors has been identified, AIS can be diagnosed after week 11 of the pregnancy.
This can be done using a procedure called chorionic villus sampling (CVS), which involves taking a sample of cells from the placenta (afterbirth) for testing.
Alternatively, amniocentesis can be used from week 15 of the pregnancy. This is where a needle is used to extract a sample of amniotic fluid so that it can be tested for genetic conditions and abnormalities. Amniotic fluid is the protective fluid that surrounds the developing baby in the womb.