Definition of Intersex:

In humans and other animals, is a variation in sex characteristics including chromosomes, gonads, or genitals that do not allow an individual to be distinctly identified as male or female.

Intersex is a group of conditions where there is a discrepancy between the external genitals and the internal genitals (the testes and ovaries).

The older term for this condition, hermaphroditism, came from joining the names of a Greek god and goddess, Hermes and Aphrodite. Hermes was a god of male sexuality (among other things) and Aphrodite a goddess of female sexuality, love, and beauty.

Although the older terms are still included in this article for reference, they have been replaced by most experts (and patients and families) because they are misleading, confusing, and insensitive. Increasingly this group of conditions is being called disorders of sex development (DSDs).

Dave Wells prefers not to use labels and will identify a person by their chosen identity.  Although DSDs maybe the new term used by some, it still identifies the gender diversity as a ‘Disorder’.  It has been labelled as a disorder due to the causes which include a number of conditions such as; ‘Congenital adrenal hyperplasia’, ‘ovarian tumours’, among others.  Dave Wells, view people who are ‘intersex’ as having a variation or diversity of their gender, rather than a condition which can also be related to an illness, which he sees as insulting.


In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females.

The 23rd pair, the sex chromosomes, differ between males and females. Females have two copies of the X chromosome (XX), while males have one X and one Y chromosome (XY).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 foetus 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 virilisation. It used to be called female pseudo-hermaphroditism.

46, XX Intersex

has several possible causes:

• Congenital adrenal hyperplasia (the most common cause).

• Male hormones (such as testosterone) taken or encountered by the mother during pregnancy.

• Male hormone-producing tumours in the mother. These are most often ‘ovarian tumors’. Mothers who have children with 46, XX intersex should be checked unless there is another clear cause.

• Aromatase deficiency. This one may not be noticeable until puberty. Aromatase is an enzyme that normally converts male hormones to female hormones. Too much aromatase activity can lead to excess estrogen (female hormone); too little to 46, XX intersex. At puberty, these XX children, who had been raised as girls, may begin to take on male characteristics.

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 under-virilization. It used to be called male pseudo-hermaphroditism. Formation of normal male external genitals depends on the appropriate balance between male and female hormones; therefore, it requires the adequate production and function of male hormones.

46, XY intersex

Has many possible causes:

• Problems with the testes:

The testes normally produce male hormones. If the testes do not form properly, it will lead to under virilization. There are a number of possible causes for this, including XY pure gonadal dysgenesis.

Problems with testosterone formation:

Testosterone is formed through a series of steps, where each requires a different enzyme. Deficiencies in any of these enzymes can result in inadequate testosterone and produce a different syndrome of 46, XY intersex. Different types of congenital adrenal hyperplasia can fall in this category.

Problems with using testosterone:

Some people have normal testes and make adequate amounts of testosterone, but still have 46, XY intersex.

• 5-alpha-reductase deficiency:  

People with 5-alpha-reductase deficiency lack the enzyme needed to convert testosterone to dihydrotestosterone (DHT). There are at least five different types of 5-alpha-reductase deficiency. Some of the babies have normal male genitalia, some have normal female genitalia, and many have something in between. Most change to external male genitalia around the time of puberty.

• Androgen insensitivity syndrome (AIS):  

This is the most common cause of 46, XY intersex. It has also been called testicular feminization. Here the hormones are all normal, but the receptors to male hormones don't function properly. There are over 150 different defects that have been identified so far, and each causes a different type of AIS.

True Gonadal Intersex:  

Here the person must have both ovarian and testicular tissue. This may 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 Diversities). Many chromosome configurations other than simple 46, XX or 46, XY can result in disorders (diversities/variations) of sex development (DSDs).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 different formations of chromosomal make-up do not result in an outcome 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.

Note: In many kids the cause of intersex may remain undetermined, even with modern diagnostic techniques.


The symptoms associated with intersex will depend on the underlying cause, but may include:

• Ambiguous genitalia at birth

• Micro-penis

• Clitoromegaly (an enlarged clitoris)

• Partial labial fusion

• Apparently undescended testes (which may turn out to be ovaries) in boys.

• Labial or inguinal (groin) masses -- which may turn out to be testes -- in girls.

• Hypospadias

• Otherwise, unusual-appearing genitalia at birth

• Electrolyte abnormalities

• Delayed or absent puberty

• Unexpected changes at puberty

Different Examinations and Tests used to determine:

• Chromosome analysis

• Hormone levels (for example, testosterone level)

• Hormone stimulation tests

• Electrolyte tests

• Specific molecular testing

• Endoscopic examination (to verify the absence or presence of a vagina or cervix)

• Ultrasound or MRI to evaluate whether internal sex organs are present (for example, a uterus).


Ideally, a Sexologist will collaborate with a team of health care professionals with expertise in intersex who should work together to understand and treat the child with intersex -- and to understand, counsel, and support the entire family.

Parents should understand controversies and changes in treating intersex in recent years.  In the past, the prevailing opinion was that it was generally best to assign a gender as quickly as possible, often based on the external genitals rather than the chromosomal gender, and to instruct the parents to have no ambiguity in their minds as to the gender of the child. Prompt surgery was often recommended. Ovarian or testicular tissue from the other gender would be removed. In general, it was considered easier to reconstruct female genitalia than functioning male genitalia, so if the "correct" choice was not clear, the child was often assigned to be a girl.

More recently, the opinion of many experts has shifted. Greater respect for the complexities of female sexual functioning has led them to conclude that suboptimal female genitalia may not be inherently better than suboptimal male genitalia, even if the reconstruction is "easier." In addition, other factors may be more important in gender satisfaction than functioning external genitals. Chromosomal, neural, hormonal, psychological, and behavioural (gender brain) factors can all influence gender identity. Many experts now urge delaying definitive surgery for as long as healthy, and ideally involving the child in the gender decision.

Clearly, intersex is a complex issue, and its treatment has short- and long-term consequences. The best answer will depend on many factors, including the specific cause of the intersex. It is best to take the time to understand the issues before rushing into a decision. An intersex support group may help acquaint families with the latest research, and may provide a community of other families, children, and adult individuals who have faced the same issues.

Support groups are very important for families dealing with intersex as they enable other people with chromosomal diversities to share experiences.  Different support groups may differ in their thoughts regarding this very sensitive topic. Look for one that supports your thoughts and feelings on the topic.

Dave Wells has a broad experience in working with people with different variations of gender and can support you to put your gender into context in your life (if required), as well as navigate through any barriers that arise.

Information adapted from:

Porterbrook Gender Clinic Resources – Sheffield, England