Key Points Disorders of sex development (DSDs) are congenital conditions in which development of chromosomal, gonadal, or anatomical (genital) sex is atypical for that expected for a male or female.Most DSDs are caused by genetic mutations in hormone metabolism or action or in gonadal development.The evaluation for a suspected DSD in the newborn period involves a detailed gestational and family history, as well as a detailed examination of genitalia.Late or atypical pubertal development, or fertility concerns, may indicate an undiagnosed DSD.Care through a specialized multidisciplinary program is optimal, but pediatricians have an important role in providing resources and psychosocial support and in navigating family discussions.