Mixed Gonadal Dysgenesis: A Narrative Literature Review and Clinical Primer for the Urologist

Mixed gonadal dysgenesis is a difference of sex development that is often confused with other conditions. Individuals have a 45,X/46,XY karyotype. Gonads are characterized by a streak gonad and a dysgenetic testis at varying levels of descent. Persistent Müllerian structures are typical (eg, hemi-uterus). There is significant phenotypic heterogeneity of the internal and external genitalia that, together with different interpretations of the definition, have contributed to a poor understanding of the condition among pediatric urologists. Mixed gonadal dysgenesis is one manifestation of the 45,X/46,XY karyotype. 45,X/46,XY mosaicism can also be associated with typical female or male external genitalia. This review aims to clarify the mixed gonadal dysgenesis definition and to provide urologists with diagnostic and management considerations for affected individuals.