Intersex
Intersex is a group of conditions where there is a discrepancy between the external genitals and the internal genitals (the testes and ovaries)
Intersex can be divided into four categories:
46, XX Intersex
46, XY Intersex
True Gonadal Intersex
Complex or Undetermined Intersex
46, XX Intersex. The person has the chromosomes of a woman, the ovaries of a woman, but external (outside) genitals that appear male. This usually is the result of a female fetus having been exposed to excess male hormones before birth. The labia ("lips" or folds of skin of the external female genitals) fuse, and the clitoris enlarges to appear like a penis. Usually this person has a normal uterus and Fallopian tubes. This condition is also called 46, XX with virilization. It used to be called female pseudohermaphroditism. There are several possible causes: (see article at link)
46, XY Intersex. The person has the chromosomes of a man, but the external genitals are incompletely formed, ambiguous, or clearly female. Internally, testes may be normal, malformed, or absent. This condition is also called 46, XY with undervirilization. It used to be called male pseudohermaphroditism. Forming normal male external genitals depends on the appropriate balance between male and female hormones; therefore, enough requires the adequate production and function of male hormones. 46, XY intersex has many possible causes: (see article at link)
True Gonadal Intersex. Here the person must have both ovarian and testicular tissue. This might be in the same gonad (an ovotestis), or the person might have one ovary and one testis. The person may have XX chromosomes, XY chromosomes, or both. The external genitals may be ambiguous or may appear to be female or male. This condition used to be called true hermaphroditism. In most people with true gonadal intersex, the underlying cause is unknown, although in some animal studies it has been linked to exposure to common agricultural pesticides.
Complex or Undetermined Intersex Disorders of Sexual Development. Many chromosome configurations other than simple 46, XX or 46, XY can result in disorders of sex development. These include 45, XO (only one X chromosome), and 47, XXY, 47, XXX -- both cases have an extra sex chromosome, either an X or a Y. These disorders do not result in an intersex condition where there is discrepancy between internal and external genitalia. However, there may be problems with sex hormone levels, overall sexual development, and altered numbers of sex chromosomes.