Androgen Insensitivity Syndrome (AIS - formerly known as Testicular Feminising Syndrome) is a genetic condition whereby, due to a variation in the development of the reproductive system, there is a complete (CAIS) or partial (PAIS) inability to utilise testosterone. People with AIS are born with testes and 46XY (male) chromosomes.

While people with AIS are relatively healthy and can expect to live a full life, one of the main risk factors for people with AIS is the risk of the testes becoming cancerous. This risk increases with age. Some studies suggest that the expectancy of tumors is 3.6% of the population with AIS at age 25 and 33% at age 50 - others estimate that the overall incidence of malignancy is somewhere between 5% and 22% (some interesting research on risk here).

Most medical professionals will encourage the testes to be removed as early as possible, though it is generally agreed that there is a relatively low incidence during infancy through to early adulthood which allows for safe postponement of gonadectomy after puberty or for at least one gonad be left until puberty to allow for the endogenous estrogen to result in secondary sex characteristics.

If you decide not to remove your ingeniual testes at this time, then you will need to carefully and regularly monitor your health with the help of your doctor (via blood testing, ultrasound and testicular biopsy) and immediate removal of the testes is advised if there is any indication of malignancy (or even pre-cancerous activity - 'in situ seminoma').

Removal of the testes requires the immediate commencement of a course of Hormone Replacement Therapy (HRT).

Osteoporosis is also a risk for people with AIS. Other complications include infertility and psychosocial issues.

For more information, please click on our Fact Sheets to download.

Androgen Insensitivity Syndrome (AIS) & similar conditions brochure ( pdf format)

A guide for parents of children with atypical genitalia brochure ( pdf format)