This description has been taken from: Pinel, J. (1993) Biopsychology. 2nd Edition. Allyn and Bacon.
Anne S., an attractive 26-year-old female, sought treatment for two sex-related disorders: lack of menstruation and pain during sexual intercourse (Jones & Park, 1971). She sought help because she and her husband of 4 years had been trying without success to have children, and she correctly surmised that her lack of a menstrual cycle was part of the problem. A physical examination revealed that Anne was a healthy young woman. Her only readily apparent peculiarity was the sparseness and fineness of her pubic and axillary hair. Examination of the external genitals revealed no abnormalities; however, there were some problems with her internal genitals. Her vagina was only 4 centimeters long, and her uterus was grossly underdeveloped.
...Anne's doctors concluded that she was a man. No, this is not a misprint; they concluded that Anne, the attractive young housewife, was in fact Anne, the happily married man. Three lines of evidence supported this diagnosis. First, analysis of some cells scraped from the inside of Anne's mouth revealed that they were of the male XY type. Second, a tiny incision in Anne's abdomen, which enable Anne's physicians to look inside, revealed a pair of internalized testes, but no ovaries. Finally, hormone tests revealed that Anne's hormone levels were those of a male.
Anne suffers from androgenic insensitivity syndrome; all of her symptoms stem from the fact that her body lacks the ability to respond to androgens. During development, Anne's testes released normal amounts of androgens for a male, but her body could not respond to them, and her development thus proceeded as if no androgens had been released. Her external genitals, her brain, and her behavior developed along preprogrammed female lines, without the effects of androgens to override the female program, and her testes did not descend from her body cavity. Furthermore, Anne did not develop normal internal female reproductive ducts because, like other genetic males, her testes released Mullerian inhibiting substance -- that is why her vagina was short and her uterus underdeveloped. At puberty, Anne's testes released enough estrogens to feminize her body in the absence of the counteracting effects of androgens; however, adrenal androstenedione was not able to stimulate the growth of pubic and axillary hair.
Money and Ehrhardt (1972) studied the psychosexual development of 10 androgen insensitive patients and concluded that the placidity of their childhood play, their goals, their fantasies, their sexual behavior and their maternal tendencies -- several had adopted children -- all "conformed to the idealized stereotype of what constitutes femininity in our culture" (p. 112). Apparently, without the masculinizing effects of androgens, infants who look like females and are raised as females come to think and act like females -- even when they are genetic males.
An interesting issue of medical ethics is raised by the androgenic insensitivity syndrome. Many people believe that physicians should always disclose all relevant findings to their patients. If you were Anne's physician, would you tell her that she is a man? Would you tell her husband? Anne's vagina was surgically enlarged, she was counseled to consider adoption, and, as far as I know, she is still happily married and unaware of her genetic sex.