Most people born with androgen insensitivity syndrome (AIS) will be infertile, as the development of the female internal organs is usually suppressed by male hormones from the testes in the body. These people will have no womb, ovaries or fallopian tubes.
Only people with very mild androgen insensitivity may be fertile.
Complete androgen insensitivity syndrome (CAIS)
In approximately half of babies born with CAIS, their undescended (internal) testes result in a hernia, which brings the condition to light during infancy. Otherwise, there are no external physical signs of the condition in infants.
The first obvious symptoms usually do not appear until puberty, when the child will:
- have no, or very little, pubic and underarm hair
- not start their periods, due to an absence of ovaries
- not experience the acne normally associated with puberty (acne is a reaction to androgen)
Also, the vagina of a woman with CAIS is usually about two-thirds the length of normal vagina (6cm/2.4 inches), and can be even shorter.
Partial androgen insensitivity syndrome (PAIS)
The development of children with PAIS will depend on their level of insensitivity to androgen. A child with a high level of insensitivity will develop as a girl during puberty, while those with a low level will develop as a boy, though there may be some breast development in the latter.
In some cases, babies with PAIS may be raised as boys but become more female as they develop during puberty. Hormone therapy can sometimes be used to "direct" puberty towards a certain gender. Or, treatment can be used to delay puberty until a child is old enough to make an informed decision about their preferred gender identity.
Grading system for AIS
The grading system used for AIS runs from grade 1 to grade 7. AIS grades 6/7 are at the CAIS end of the spectrum and children are usually brought up as girls. In those with PAIS, genital appearance can be anywhere from completely female (grade 5) to completely male (grade 1). Very slight androgen insensitivity may contribute to infertility in some men.
- Grade 1 – PAIS – Male genitals, infertility
- Grade 2 – PAIS – Male genitals, but they may be small. The opening of the urethra (urine tube) may also be on the underside of the penis (known as hypospadias).
- Grade 3 – PAIS – Predominantly male genitals, but very small. May have hypospadias and undescended (internal) testes.
- Grade 4 – PAIS – Ambiguous genitals. The structure of a penis may be there, but is so small it is not possible to determine whether it is a penis or a clitoris.
- Grade 5 – PAIS – Essentially female genitals, including separate urethral and vaginal passages. Clitoris may appear enlarged.
- Grade 6 – PAIS – Female genitals with pubic and underarm hair.
- Grade 7 – CAIS – Female genitals with little or no pubic and underarm hair.
