What are differences of sex development, or DSDs?

Differences of sex development (DSDs)—formerly referred to as intersex conditions—are a group of congenital conditions in which an individual’s anatomical sex, genetic constitution, or reproductive anatomy does not align with typical binary definitions of male or female.1

These variations can arise from several biological factors:

• Sex Chromosome Variations: Some DSDs involve atypical sex chromosome complements, such as Turner syndrome or Klinefelter syndrome.1
• Hormonal and Genetic Factors: Other categories involve mutations in genes on autosomal chromosomes or abnormalities in hormone function, such as issues with testosterone biosynthesis or receptor sensitivity.12
• Anatomical Variations: These may include conditions like 46,XX DSD (female virilization), 46,XY DSD (abnormalities in testicular differentiation), or ovotesticular disorder, where an individual possesses tissues from both ovaries and testes.1

Because human sexual differentiation is a complex process involving precise genetic and hormonal signaling during fetal development, there are various points where development may diverge from the typical path. The categorization of these conditions remains a subject of ongoing scientific and clinical discussion.21