True hermaphroditism

True hermaphroditism is a medical term for an intersex condition in which an individual is born with ovarian and testicular tissue.

There may be an ovary underneath one testicle or the other, but more commonly one or both gonads is an ovotestis containing both types of tissue.

There are no documented cases in which both types of gonadal tissue function. Encountered karyotypes are 47XXY, 46XX/46XY, or 46XX/47XXY, and various degrees of mosaicism (with one interesting case of an XY predominant (96%) mosaic giving birth).^[1]

Although similar in some ways to mixed gonadal dysgenesis, the conditions can be distinguished histologically.^[2]

Although fertility is possible in true hermaphrodites (as of 2010 there have been at least 11 reported cases of fertility in true hermaphrodite humans in scientific literature),^[2] there has yet to be a documented case where both gonadal tissues function; contrary to rumors of hermaphrodites being able to impregnate themselves.

Presentation

External genitalia are often ambiguous, the degree depending mainly on the amount of testosterone produced by the testicular tissue between 8 and 16 weeks of gestation.

Causes

This condition is very rare. There are several ways in which this may occur.

• It can be caused by the division of one ovum, followed by fertilization of each haploid ovum and fusion of the two zygotes early in development.
• Alternately, an ovum can be fertilized by two sperm followed by trisomic rescue in one or more daughter cells.
• Two ova fertilized by two sperm will occasionally fuse to form a tetragametic chimera. If one male zygote and one female zygote fuse, a hermaphroditic individual may result.
• It can be associated with mutation in the SRY gene.^[3]

References

Wikimedia Commons has media related to Hermaphroditism in humans.