UCLA

Key PointsDisorders of sex development (DSDs) are defined as congenital conditions in which development of chromosomal, gonadal, or anatomic sex is atypicalMutations in genes that encode transcription factors, signalling components and epigenetic modifiers that are involved in sex determination can result in 46,XX and 46,XY DSDsAt 6–8 weeks post-conception in human fetal development, upregulated expression of SRY in the bipotential gonad promotes testis determination, whereas activation of WNT4 and RSPO1 signalling promotes ovary determinationGonadal phenotypes in patients with DSDs range from gonadal dysgenesis (in which the gonads are fibrous streak gonads) to varying degrees of ovotesis (in which both ovary and testicular tissue are present)The complexity and interrelatedness of factors that contribute to the aetiology and the medical and psychological outcomes of DSDs demand a multidisciplinary team approach to health careIn contrast to gender differences in activities and interests, associations between prenatal exposure to androgens and development of gender identity or sexual orientation are unclear