Hermaphroditism raises a major question: How is sex determined? The determination of sex is a very useful concept to appreciate the nature of the different variables of existing hermaphrodites. Sex can be determined at four different levels: genetic sex is determined by the presence or absence of a Y-chromosome. No matter how many X-chromosomes are present, a single Y-chromosome dictates testicular development and the genetic male gender. The indifferent gonads before the 7th week of fetal life have inherent tendency to feminize unless influenced by Y-chromosome dependent masculinizing factors.
Gonadal sex is based on the histologic characteristics of the gonads. Ductal sex depends on the presence of derivatives of the Mullerian or Wolffian ducts present during fetal life. Phenotypic or genital sex is based on the appearance of the external genitalia. Sexual ambiguity, as seen in hermaphrodites, is present whenever there is disagreement among these various criteria for sex determination (Robbins and Cotran, 2006)3 HERMAPHRODITE LABELS4 Hermaphrodites exist in two main forms: true and pseudo-hermaphrodites. The term true hermaphrodite implies the presence of both ovarian and testicular tissue.
In contrast, a pseudo-hermaphrodite represents a disagreement between the phenotype and gonadal sex. All are equally genuine. Hermaphroditism occurs rarely in human populations, accounting for about 1%. TRUE HERMAPHRODITES A person born with both ovary and testicular tissue, this could be 2 separate gonads (one of each) or a combination of both in one (an ovotestes). The genitalia can vary from completely male or female, to a combination of both or even ambiguous looking. The chromosome (karyotype) compliment can be XX (female), XY (male), XX/XY (mosaic) or even XO (extremely rare).
Those XX with female genitalia are raised female (some have even given birth). Those XY with male genitalia are raised male (a few have fathered children). The children born XX/XY or XO (with genitalia male or female) are raised in the sex they look most like. CAUSES The causes are not known, the medical community does know this is a very rare condition but do not have accurate figures to how many people have this condition (depending on the literature between 350-450 known cases). The karyotype is 46, XX in 50% of patients; of the remaining, most are mosaics with a 46, XX/46, XY karyotype.
Only rarely is the chromosome constitution 46, XY. (Robbins and Cotran, 2006) FEMALE PSEUDO-HERMAPHRODITES [FERM] A person born XX with normal female internal organs but with “masculanized” genitalia. They can appear more male then female or a combination of each. CAUSES The most common is Congenital Adrenal Hyperplasia (CAH). It occurs approximately in 1:14,000 births. This is when the adrenal glands overproduce testosterone. It also has been recorded that some persons with this disorder had been exposed to progesterone-like drugs before they were born.