Androgen insensitivity syndrome: What to know

Androgen insensitivity syndrome: What to know

The disease of androgen insensitivity is an unusual genetic condition in which male hormones do not respond to a male fetus.

The disorder affects the growth of the genitals and the reproductive system.

It is also known as Reifenstein syndrome, Rosewater syndrome, incomplete testicular feminization, or Type 1 familial incomplete male pseudohermaphroditism.

A newborn with androgen insensitivity syndrome (AIS) tends to be female, although it is rare to have reproductive characteristics. The scale of the vagina and the lack of ovaries , fallopian tubes, or the womb can be abnormal. The testicles can stay in the abdomen or inguinal canal.

AIS impacts between 2 and 5 of every 100,000 people in the United States (U.S.).

Individuals with AIS have a normal life span but will need clinical support and hormone therapy.

Important facts about androgen insensitivity syndrome

  • Androgen insensitivity syndrome (AIS) causes the development of abnormal sexual organs.
  • The condition is genetic and affects the Y chromosome that shapes male sexual development.
  • AIS can be graded on a scale from one to 7. One is very mild, and 7 refers to complete AIS.
  • Gender identity is an extremely important concern for people with AIS, as their genitals may be male at an internal level but female in appearance. Counselling can assist with this.
  • Undescended testicles can be released or removed by surgical means, and hormone therapy may be used to nurture a person with AIS towards their preferred gender.

What are sex chromosomes?

Androgen insensitivity syndrome
Androgen insensitivity syndrome is caused by a mutation to the Y chromosome that programs male sexual development.

Sex chromosomes are a pair of molecules of DNA, called X or Y, that determine the sexual development of an individual.

  • A female has two X chromosomes known as XX
  • A male has one X and one Y chromosome, or XY

The Y chromosome induces the testes to develop and prevents the growth of the female ovaries. The female reproductive system and genitals grow spontaneously because there is no Y chromosome.

Male genitals and reproductive organs should be produced by an child born with XY chromosomes. The male reproductive organs that contain androgens, or male hormones, are the testes, or testicles. These hormones allow male traits and sex organs, such as the penis, to develop.


Both male and female embryos have the same genitals for the first 8 weeks of growth. Either a female or male reproductive system can develop.

A healthy XY embryo will develop male genitals, as the testes will release androgens.

Since a genetic change results in a limited number of androgen receptors, the body of a person with AIS will not respond to the androgen. Full androgen insensitivity syndrome (CAIS) can contribute to a complete loss of response.

Instead of falling to the scrotum, the testicles remain in the body. The genitals, seen from outside the body, would mimic those of a person.

An individual with AIS inherits the mutated gene from their mother in 70 percent of cases.

A carrier may be a female with one abnormal X chromosome. A carrier is a woman who has the impaired gene while contemplating AIS and can carry it on without feeling its effects. Her female offspring may also be carriers, and the disease may be due to her male offspring.

Other cases are thought to arise from a defect that occurs either before the eggs of the mother are created or shortly after conception of an embryonic cell. However, the precise explanation is unclear.

AIS is an intersex disorder that is distinct from dysphoria in gender. An individual with gender dysphoria produces natural reproductive organs and genitals, but believes it is not true for their assigned sex. Gender dysphoria is encountered by people who are transgender.


There are 3 forms of androgen insensitivity syndrome:

  • Complete: A person with CAIS will have female external genital features, and is likely to develop as a female.
  • Partial: In partial androgen insensitivity syndrome (PAIS), there is some sensitivity to androgen. Depending on the level of sensitivity, the person may appear completely male or female, or they may have some features of both sexes. Children born with this condition may grow into either females or males, depending on their degree of androgen sensitivity and subsequent genital development.
  • Mild: Mild androgen insensitivity syndrome (MAIS) affects males during puberty. They may form female breast tissue. A boy with MAIS may also not be able to produce effective sperm.

Signs and symptoms

A typical symptom of AIS is infertility, but it does not occur in mild cases.

It would not develop the internal reproductive organs of females born with AIS, causing infertility. Non-development of reproductive organs is attributed to the release of male hormones by testes in the body.

Complete androgen insensitivity syndrome

If an inguinal hernia is present in a child, it could be due to undescended examination. In children, between 0.8 and 2.4 percent of inguinal hernia cases are due to CAIS.

Normally, at birth, there are no outward signs or symptoms, and the disorder does not manifest before the person reaches puberty. When the person may not grow pubic or underarm hair, CAIS will become evident, and menstruation may not begin.

Females experiencing CAIS will have a short “ pouch ”vagina.

Partial androgen insensitivity syndrome

Child growth is impaired by partial androgen insensitivity. During puberty, an individual with high insensitivity may grow as a girl. Those with low insensitivity will develop as boys, but breasts may start to develop. They may have a clitoris that is somewhat enlarged or an almost completely developed penis.

A child will develop as a boy, but with the onset of puberty, more female traits develop.


Androgen insensitivity, if the genitals look irregular, may be detected at birth. For eg, this may be detected if the presence of the genitals does not correlate to that expected by prenatal amniocentesis.

Chorionic Villus Sampling (CVS) can show AIS during pregnancy. In CVS, for research, cells are drawn from the placenta.

A physician may diagnosis AIS if a woman has an inguinal hernia, is having difficulties conceiving, or has physical problems with sexual intercourse.

A blood test can confirm the diagnosis by measuring hormone levels and detecting the altered chromosome.

The soft tissues and cavities within the body are illustrated by an ultrasound scan. The lack of female reproductive organs can be indicated by this.

Unborn infants, although there is a family background, are not regularly screened for AIS.

The disorder can be rated from 1 to 7 after checking. Grade 7 refers to CAIS, while grades 1 to 6 indicate that there is PAIS for a child.

The genitals tend to be feminine in grade 7. A individual with grade 1 AIS may have male genitals but is likely to be infertile.


Because of their outwardly feminine genitals, children with CAIS are commonly regarded as males, but often parents have to consider whether to raise their child as a male or a female. When the genitals have both male and female traits, this may be complicated.

Hormone therapy can help guide development into a particular gender during puberty. It may even prolong puberty until the infant is old enough to assess which gender is acceptable.

Counseling will also help determine a gender for a child with AIS.

Most PAIS children maintain the sex they were assigned at birth, but some believe that this does not reflect their true identity and want to alter.


When the infant was young and a gender had been identified, reconstructive genital surgery was done. It is usually delayed nowadays before the child can tell.

When a woman has testicles, they could be removed by a doctor because they may become cancerous. This is listed as an orchidectomy.

The procedure is typically performed after adolescence, since the testes may transform androgen to estrogen. The hormone that promotes female sexual activity is estrogen.

Waiting to perform an orchidectomy well after puberty helps a girl with AIS to develop a feminine body without hormone therapy.

Orchiopexy may be needed for a person with testicles embedded in the abdomen. Orchiopexy is a surgical technique intended for the release into the scrotum of an undescended testis.

Surgery to lengthen the vagina is another choice. For a person with AIS, this may facilitate sexual intercourse. After puberty, this treatment is usually done, helping the individual to make an informed decision.

Few women prefer to reduce the clitoris surgically and to widen the vaginal opening. This can contribute to a partial clitoral loss of sensitivity.

After finishing puberty, women with complete androgen insensitivity who have their testes removed may undergo hormone therapy.

Supplements of estrogen can avoid signs of menopause, including the onset of osteoporosis. As their Y chromosome carries genes for taller growth, they may also stop a woman from being too tall.

If the testes are removed at a young age, hormone therapy can begin to induce puberty at about 10 or 11 years of age.

To promote such male characteristics, such as the development of facial hair and a deeper voice, boys with partial insensitivity may require androgen supplements.

For both the person with the disorder and their parents, social assistance is often important.