Disorders of sexual differentiation: I. Genetics and pathology

Objectives: To provide a summary of the recent major advances in the field of molecular genetics and understanding of psychosexual development, as these developments have resulted in changes in terminology and classification of disorders of sexual differentiation (DSD)/intersex; and to provide a quick and simplified review of the basic information. Methods: Recent publications (over the last 10 years) were identified by a Pub- Med search, as were relevant previous studies, using the keywords; ‘sex chromo- somes’, ‘psychosexual development’, ‘classifications’, ‘disorders of sexual differentiation’, ‘Chicago consensus’, ‘gonadal malignancy’, ‘intersex’ and ‘ambigu- ous genitalia’. Results: The newly proposed terminology and classification has eliminated some confusion for both patient and family, as well as among health professionals. The new advances have facilitated the categorisation of gonadal malignancy in patients with DSD into high-, intermediate-and low-risk groups. Conclusions: The major changes in terminology and classification of DSD should be considered as the first steps on a long road of research effort. The current available data remain far from sufficient. More molecular genetics studies will allow a better understanding of the causes of each condition of DSD.