Brief overview of differences of sex development

Differences of sex development, often referred to as dsd, are a large and mixed group of conditions. Below we give an incomplete overview of some common and some less common conditions, with some very short descriptions. Parents have told us that it is helpful for them and their children to see the name of ‘their’ specific condition alongside all the other ways bodies can develop.

What’s in a name?

We have used the names that parents use, whether it is the condition-specific name, or the protein/enzyme or gene that makes the body develop differently. We want parents, young people and children to ‘recognise’ the name that has been used to describe ‘their’ different sex development. We hope you will find that this is the place to get further information. Our list might therefor be (a little bit) different from a typical medical way of listing conditions. We will continue to develop it with input from young people, families and healthcare professionals.


We have tried to give some information about how often different sex development happen. Sometimes all we can say is ‘Rare’ because we don’t have a reliable way (not in the UK nor elsewhere) to keep track of numbers and the different types of diagnoses. Doctors, in the UK, Europe and internationally, are working together so we can get better statistics and a better understanding in this area so that psychological and medical healthcare can be better targeted. It’s good to know that this applies to all rare conditions, not just dsd!

It is helpful to know also that some conditions have “hotspots” in different countries – this means, there might be some areas where one or other conditions are seen more frequently, and others where conditions are seen very infrequently. So when looking at ‘prevalence’ (how often) be aware that this is variable and that numbers can change as our understanding of these conditions improves.