Disorders of sex development
Disorders of sex development (DSDs) are a group of rare conditions where the reproductive organs and genitals don't develop as expected.
If you have a DSD, you'll have a mix of male and female sexual characteristics.
You may have sex chromosomes (bundles of genes) normally associated with being female (XX chromosomes) or male (XY chromosomes), but your reproductive organs and genitals may be:
- of the opposite sex
- not clearly male or female (ambiguous or atypical)
- a mixture of male and female
This occurs because of a difference with your genes and/or how you respond to the sex hormones in your body. It can be inherited, but it often occurs randomly for no clear reason.
The most common times to find out that a child has a DSD is at birth or during adolescence.
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.
What happens after birth
Some DSDs are suspected soon after birth because of obvious signs such as undescended testicles or an atypical genital appearance.
A number of tests may be carried out to help confirm the diagnosis and identify any medical problems that may require immediate treatment.
These tests may include a further physical examination of your baby carried out by a specialist, an ultrasound scan to examine their internal organs, and blood tests to check their genes and hormone levels.
Your care team may advise you to delay registering your child's birth for a few days while these tests are carried out.
Afterwards, the results will be explained to you and you'll have a discussion about whether you'd like to bring your baby up as a boy or a girl.
Emergency treatment is rarely needed, but the team of specialists will also talk to you about your options regarding immediate or delayed treatment with hormone therapy or surgery.
DSD Families has a leaflet with more information about what happens when your baby is born with genitals that look different (PDF, 1.7Mb).
Advice for parents of older children
Sometimes a DSD may be diagnosed if an older child doesn't develop normally in puberty. For example, your child may not start the normal puberty changes, or may start puberty but not get periods.
Speak to your GP if you have any concerns about your child's development at puberty. They can refer your child to a specialist, usually a consultant in paediatric endocrinology or an adolescent gynaecologist.
A team of different healthcare professionals will work with you to understand your child's condition, and offer you and your child support and advice.
As your child grows up, they may need hormone therapy and psychological support, and they may eventually decide they want surgery to change their appearance.
With the right care and support, many people with DSDs come to terms with their condition and live happily.
If you think you have a DSD
If you think or know you have a DSD, help and support is available.
Speak to your GP initially, as they'll be able to refer you to a team of specialist healthcare professionals who can offer support and advice.
Most people with a DSD stay with the gender they were assigned as a baby, but if you feel the gender you were assigned doesn't represent who you are, you may wish to change your gender. This will be something you can discuss with your care team.
If you have a DSD, you may be infertile, and may need hormone therapy and psychological support. The right care and support can help you come to terms with your condition and lead a normal life.
Support groups
If you have a DSD or you're the parent of a child with a DSD, you may find it useful to contact or join a support group.
These groups can often offer more information and advice about living with a DSD, and may be able to put you in contact with others who've been in a similar situation to you.
National DSD support groups include:
- Androgen Insensitivity Syndrome Support Group
- Congenital Adrenal Hyperplasia Support Group
- DSD Families
- MRKH UK
You may also want to ask your care team about support groups in your local area.
Terminology
Disorders of sex development is a new term increasingly used by doctors to describe a group of conditions where the development of the reproductive organs is different from what's usually expected.
But not everyone agrees with the word "disorder" and some people prefer to use terms like "differences in sex development" or "diversity of sex development".
Others find the word "intersex" a more helpful way to describe themselves.
Your doctor should explain the different terms used, and you can choose which you feel most comfortable with.