Pseudohermaphroditism

Pseudohermaphroditism, or pseudo-hermaphroditism, is a name used to describe organisms born with secondary sex characteristics or a phenotype which is different from what would be expected based upon the gonadal tissue (ovary or testis).

In some cases, the external sex organs look intermediate between the typical clitoris or penis. In other cases, the external sex organs have an appearance that does not look intermediate, but rather has the appearance that would be expected to be seen with the "opposite" gonadal tissue. Because of this, pseudohermaphroditism is sometimes not identified until puberty. It is possible for the condition to be undetected until adulthood.

The term "male pseudohermaphrodite" is used when a testis is present, and the term "female pseudohermaphrodite" is used when an ovary is present. The term "true" hermaphrodite is reserved for the very rare cases where both ovarian and testicular tissue is present. (Whether or not that term would be appropriate when ovotestes are found, or only when distinct ovaries and testes are found, is not well defined.)

Associated conditions in males include 5-α-reductase deficiency from a deficiency in the male chromosome (46 XY).

Surgery
Surgery has sometimes been performed to alter the appearance of the genitals.

Terminology
Use of the term "pseudohermaphroditism" can be problematic. The term "pseudohermaphroditism" was created by Edwin Klebs in 1876, long before the genetic roles of the X chromosome and Y chromosome and the social components of gender identity were well characterized, which is why the term is usually used to describe the dissonance between gonadal histology and external genital appearance.

The term "intersexuality" was introduced by Richard Goldschmidt in 1923. However, the term "intersex" has also been challenged; the Lawson Wilkins Pediatric Endocrine Society and the European Society for Pediatric Endocrinology have adopted a nomenclature system based on disorders of sex development which covers "congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical" and thus replaces many disparate terms, including but not limited to those based on "hermaphrodite."

One example of the challenges involved in the use of the term is the case of women with Complete Androgen Insensitivity Syndrome (CAIS). These women often have primary and secondary sexual characteristics typical of other women; however, they are genetically XY and have internal testes, rather than ovaries. They may marry but cannot have children. However scientifically precise the description "male" pseudohermaphrodite may be for such women, it is clearly socially inappropriate. CAIS is considered little better by some, as the S for syndrome in CAIS does not accord with the "normality" many CAIS women feel about their bodies.

In humans beings, the sex status is defined at four levels: chromosomal (XY; XX), internal organs (ovaries; testicles), external organs (breasts, vulva + vagina; penis), and psyche (sexual identity). In a XX human the default development process results in a female. In a XY human a set of genes on the Y chromosome trigger a cascade of events resulting, "if all goes well", in a male. A complete female or male developmental process entails the expression of female and male sex hormones, respectively, and of their corresponding receptors in the target tissues. Without these hormones and their receptors, the internal and external sex organs, and psyche, will not develop as expected. Sex hormones, their receptors, and downstream signal transduction proteins are coded by genes that may be genetically defective.

All these factors mean that genetic mutations can block the sexual development process at three stages: (a) before the development of the internal sex organs; (b) after the development of the internal sex organs but before the development of external sex organs; and (c) after the development of external sex organs but before the maturation of the sexual component of the psyche.

While in (a) the XY human will be indistinguishable anatomically and psychologically from a female; in (b) the individual may either be born with ambiguous external genitals or have genitals apparently in the normal range at birth but, at pubertal age, not develop secondary sexual characteristics at all or develop secondary sexual characteristics which do not match the external genitals; and in (c) the individual will be transgendered (formerly referred to as transsexual).

There are other intersexual states that are not the result of the genetic configurations above.

In particular, where either the individual is a genetic mosaic (resulting from a fusion of two distinct embryos, one male and one female, during fetal development), or the individual contains duplicated chromosomes in the genome (XXY; XXXY). In the former case some tissues will be in the XX and others in the XY configuration; in the latter, all cells contain the Y chromosome and may or may not use it. This is a gynandromorph, which has both female and male characteristics at all four levels and may have either ambiguous sex organs (the XY/XX configuration may not be evenly distributed throughout the body) or unambiguous male and female sex organs (hermaphrodite).

History
John Money is perhaps the best known early researcher in this area. His doctoral thesis was titled Hermaphroditism: An Inquiry into the Nature of a Human Paradox, and awarded by Harvard University in 1952. Money was forced to change his mind about several of his early views in the course of his career (see main entry David Reimer).

Milton Diamond has probably become the best known expert public advocate for the intersex community in the early 21st century. He is the director of the Pacific Center for Sex and Society.