Disorders of sex development (DSDs) are a group of conditions where the reproductive organs and genitals do not develop normally.
If you have a DSD, you will have a mix of male and female sexual characteristics. For example, you may be female but have XY (male) chromosomes and internal testes, or you may be female with normal internal organs such as the uterus (womb) and ovaries, but have an enlarged clitoris that resembles a penis.
The disorder occurs because there is a problem with your genetic make-up and/or how you respond to the sex hormones in your body.
It is not known how common DSDs are, but they are estimated to affect 0.1-2% of the UK population.
Identifying a DSD
There are different types of DSD, and each has a different cause. Below are some examples.
Female with ambiguous (not typically male or female) or male-looking genitals
Some women have XX (female) chromosomes with normal ovaries and uterus but their genitals appear ambiguous or male. For example, they may have an enlarged clitoris resembling a penis and their lower vagina may be closed.
Doctors refer to this condition as 46,XX DSD.
The most common cause is a condition called congenital adrenal hyperplasia (CAH). If your child has CAH, they lack a particular enzyme (protein) that their body needs to make the cortisol and aldosterone hormones.
Without these, the body produces more androgens (male sex hormones). If the affected child is female, then the raised androgen levels before birth cause the genitals to become more male in appearance. This condition also has serious implications for general health.
For support and more information on CAH, visit the CAH support group.
Male with female-looking genitals
Some people have XV (male) chromosomes but their external genitals may appear entirely female or ambiguous (not clearly male or female). Testes may be absent or not properly formed.
Doctors refer to this condition as 46,XY DSD.
There are several different causes. One possible cause is androgen insensitivity syndrome (AIS), where the body ignores the androgens (male hormones) or is insensitive to them, so development is female. The testes usually remain inside their body and the uterus (womb) does not develop.
AIS is thought to occur in one in every 20,400 births, although the exact figures are unknown.
The AIS Support Group can put you in touch with other people and families with AIS.
A mix of male and female characteristics
People with this type of DSD may have male chromosomes, female chromosomes or both. Physically, they 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.
Doctors refer to this condition as 46,XX ovotesticular DSD.
Normally formed genitals but abnormal sexual development
Some people have neither the normal male (XY) nor female (XX) set of chromosomes – for example, they may only have one X chromosome (XO), or they may have an extra chromosome (XXY).
Physically, their male sex organs are normally formed as either male (testes and a penis) or female (ovaries, womb and a vagina), but they may not go through normal sexual development at puberty.
Doctors refer to this condition as sex chromosome DSD.
An example is Turner syndrome, where a female is missing an X chromosome. Girls or women with Turner syndrome are usually infertile and their height is shorter than average.
Advice for parents
If you are concerned that your child may have a DSD, speak to your doctor. They will be able to refer your child to a specialist, usually a consultant in paediatric endocrinology.
The consultant will then be able to introduce you to a team of different healthcare professionals who will work together to understand your child's condition and offer you and your child support and advice.
You can also contact DSD Families for advice and support.
As your child grows up, they may need hormone therapy and psychological support. However, 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 that you have a DSD condition, help and support is available.
You should speak to your doctor, as they will be able to refer you to a team of healthcare professionals who will work together to understand your condition and offer you support and advice.
Most people with a DSD stay with the gender they were assigned as a baby, but if you feel that the gender you were assigned does not represent who you are, you may wish to change your gender. This will be something you can discuss with your team of specialists.
If you do have a DSD, you may find that you are infertile and you may need hormone therapy and psychological support. With the right care and support, many people with DSDs come to terms with their condition and live normal lives.