Androgen Insensitivity Syndrome

In normal fetal development, females are the ‘default’ gender meaning that unless the embryological tissues are given other signals, the child will be female. To produce a male, a gene on the Y chromosome, called the SRY gene, must initiate the development of the embryological gonads into testes. The testes then must produce testosterone, a type of androgen, that will bind to the surface of the cells that form the embryonic sex ducts. This will give the signal to the cells to form male sex organs.

A recent article in Discover magazine called “The Curse of the Garcias” (December 2000) discusses a woman with androgen insensitivity syndrome. In the case of people with this syndrome, everything about male development occurs normally with the exception of the cells that form the embryonic sex ducts. Because of an error on a gene on the X chromosome, these cells do not recognize testosterone so they develop female genitalia. The individual is male in the sense that he has a Y chromosome and testes, though they usually remain in the abdomen. The female genitalia that form are incomplete and individual is unable to produce children.

Because androgen insensitivity syndrome is caused by an error on the X chromosome it is inheritable. In the article, the woman explains that it is called the “Curse of the Garcias” because many of the women in her Mexican village are unable to bear children. Most likely all of these women suffer from androgen insensitivity syndrome.