Until a few years ago, intersex was considered a disorder, that is, having sexual characteristics intermediate between those that are typical in men and those that are typical in women.

Today the conception of what intersex is is changing as knowledge of human biology expands and awareness of sex and gender diversity increases.

What is intersex?

The term “intersex” refers to a series of variations in sexual organs and characteristics, both anatomically and genetically, that cause a person to have female and male characteristics simultaneously.These variations can affect chromosomes, hormones, genitals and/or secondary sexual characteristics , such as muscle and fat distribution.

The result of the variations that produce intersexuality is the ambiguity of sexual anatomy or the discrepancy between genotype and phenotype.In summary, we can say that intersex people are those who are born without all the physical traits that are typically female or male.Moreover, since this does not necessarily have to manifest itself externally but can also occur only in the genes, not all intersex people know that they are .

The biological sciences currently conceive intersexuality as a set of disorders or variations in sexual development . The second conception, which is less stigmatizing for intersex people, is becoming more widespread.

Although many cases have been medically treated, intersexuality is not usually a threat to survival, although in some cases it does carry a risk of pain and infertility and can cause discomfort with respect to sexual identity.

Synonymous with “hermaphrodite”?

Previously intersex people were known as “hermaphrodites” but today this term is considered derogatory: hermaphroditism consists of the simultaneous presence of male and female reproductive organs that occurs in some species of animals and plants.

In ancient and medieval Europe people with ambiguous sexual characteristics were considered hermaphrodites . The law of these societies stated that they should be considered men or women according to the predominant external features. To a large extent, this conception has been maintained to this day.

During the 20th century the term “intersexuality”, coined by geneticist Richard Golschmidt in 1917, replaced “hermaphroditism” in this type of case. Medical advances during the past century allowed the popularization of surgical and hormonal interventions to alter the anatomy of intersex people so that their bodies were more similar to the prototype of the male or female.

However, the dubious effectiveness and risks of these treatments, which are often practiced on minors without their consent, have contributed to the emergence of movements that defend the rights of intersex people.

Causes and Types of Intersex

There are many possible causes of intersex that result in different variations in genotype and phenotype. These causes can be divided into four main categories according to their most defining characteristics.

Intersex 46, XX (with virilization)

In these cases the person’s chromosomes correspond to those typical of women, but their external genitalia are those of a man. Although in 46, XX intersex the person has a uterus , exposure to high levels of male hormones during fetal development, produced by various possible causes, causes the clitoris and vaginal lips to develop like a penis.

The most common cause of this type of intersex is congenital adrenal hyperplasia , which consists of defects in the adrenal glands that cause excessive secretion of androgens, as well as deficiencies in cortisol and other hormones. This disorder can influence menstruation and hair growth, but in severe cases it can also affect heart rate or blood levels of sodium and potassium.

The presence of ovarian tumors and consumption of male hormones during pregnancy by the mother can also cause intersex with virilization.

2. 46, XY Intersex (with undervirilization)

46, XY intersex consists of the presence of male chromosomes and external female or ambiguous genitalia. In this type of intersexuality the normal development of the male phenotype from the inhibition of female characteristics is not completed.

The most common cause of intersex with undervirilization is androgen insensitivity syndrome ; in these cases the body is resistant to the male hormones, necessary for the development of the gonads and the rest of the male sexual characteristics.

Malformations in the testicles and deficient testosterone production are also frequent causes of 46, XY intersex.

3. True gonadal intersexuality

This type of intersex occurs when the person simultaneously has ovaries and testicles , either completely or incompletely. In the past, these variations were known as “true hermaphroditism”, as opposed to the terms “female pseudohermaphroditism” and “male pseudohermaphroditism” which were used for XX and XY intersex, respectively.

In true gonadal intersex, the external genitalia may be male, female, or intermediate. Chromosomes XX, XY, or both may be present. The cause of these variations is unknown.

4. Complex or undetermined intersexuality

We speak of complex or indeterminate intersexuality when sexual development is altered without there being any incongruence between genotype and phenotype . Among other aspects, sex hormones or the number of chromosomes may be affected.

For example, this category would include cases where there are two X chromosomes (47, XXY or 47, XXX) and where there is only one X chromosome (45, XO).