International networks for supporting research and clinical care in the field of disorders of sex development.

Differences or disorders of sex development (DSD) are a wide range of relatively rare conditions with diverse pathophysiology that most often present in the newborn or the adolescent. Given their rarity and the need for input from a range of clinical disciplines, the management of the child with a complex form of DSD may be quite complicated, and the situation is worsened by a lack of evidence for many diagnostic and interventional procedures that are undertaken. It is, therefore, not surprising that there will be variation in the management as well as the outcome of patients with this group of conditions. By working as a network of clinical and research centres it is possible that these variations can themselves be better managed and studied. Over the last decade there has been a major shift in the field of rare diseases towards greater collaboration in clinical as well as research activity, and this chapter will summarise these developments.