Types of DSDs
There are many different types of DSD. Here are some examples:
Female genes with ambiguous or male-looking genitals
Some people have XX (female) chromosomes with normal ovaries and womb, but their genitals may not be what's usually expected in females.
For example, they may have an enlarged clitoris resembling a penis and their vagina may be closed.
Doctors refer to this condition as 46,XX DSD.
The most common cause is congenital adrenal hyperplasia (CAH). If your child has CAH, they lack a particular enzyme their body needs to make hormones called cortisol and aldosterone.
Without these, the body produces more androgens (male sex hormones). If the child is female, the raised androgen levels before birth cause the genitals to become more male in appearance.
CAH can also lead to serious health issues, such as life-threatening kidney problems that need to be treated as soon as possible.
For support and more information on CAH, you can visit the CAH support group.
Male genes with female genitals but some internal male structures
Some people have XY (male) chromosomes, but their external genitals may appear entirely female or atypical. The womb may be present or absent and the testicles may remain in the body or not form properly.
Doctors refer to this condition as 46,XY DSD.
There are several different causes of this condition. One possible cause is androgen insensitivity syndrome (AIS), where the body ignores androgens or is insensitive to them, so external development is female.
For support and more information on AIS, you can visit the AIS Support Group.
Normal genitals but abnormal sexual development
Some people have neither XY nor XX chromosomes – for example, they may only have one X chromosome (XO), or they may have an extra chromosome (XXY).
Their sex organs are normally either male or female, but they may not go through normal sexual development at puberty. For example, a child with female sex organs may not start having periods.
Doctors refer to this condition as sex chromosome DSD.
One type is Klinefelter syndrome, which is where a boy is born with an extra X chromosome (XXY).
This can mean they don't produce enough testosterone, the sex hormone responsible for the development of male characteristics and important for maintaining bone strength, sex drive and fertility in men.
Another type is Turner syndrome, which is where a girl is missing an X chromosome. Girls and women with Turner syndrome are usually infertile and their height is shorter than average.
Female with normal genitals but an absent womb
Some females are born with an underdeveloped or absent womb, cervix and upper vagina, but the ovaries and external genitalia are still present and they still develop breasts and pubic hair as they get older.
This is known as Rokitansky syndrome (also called Mayer-Rokitansky-Küster-Hauser or MRKH syndrome). The cause isn't clear, but it's not related to chromosomes because girls and women with it have the normal XX chromosomes.
Often the first sign is that a girl doesn't start having periods. Sex may also be difficult because the vagina is shorter than normal.
As they have no womb, women with Rokitansky syndrome cannot become pregnant, but it's sometimes possible to take eggs from their ovaries, fertilise them, and implant them in another woman (surrogate).
For support and more information on Rokitansky syndrome, you can visit the websites of MRKH UK, Living MRKH and the MRKH Organization.
A mix of male and female characteristics
People with this very rare type of DSD have both ovarian and testicular tissue – for example, one ovary and one testis – and their genitals may appear female, male or a mix of both.
Most people with this type of DSD have XX (female) chromosomes. The cause isn't usually clear, but some cases have been linked to genetic material normally found on the Y chromosome being found on the X chromosome.
Doctors refer to this condition as 46,XX ovotesticular DSD.
Introduction 