Pure XY gonadal dysgenesis and agenesis in monozygotic twins.

Objective: To report a case of monozygotic twin sisters who had discordant gonadal dysgenesis although each had a normal 46,XY karyotype.

Methods: Case report. Methods: University tertiary hospital. Methods: Seventeen-year-old twin sisters, one with gonadal agenesis and the other with pure gonadal dysgenesis followed by dysgerminoma. Methods: Blood samples were obtained for karyotyping and short tandem repeat polymorphism analysis (10 markers). Both patients underwent gonadectomy. Methods: Both sisters are well at time of report after gonadectomy for the sister with dysgerminoma and diagnostic laparoscope for the other.

Results: Dysgerminoma and atrophic ovarian stromal and tubal structures.

Conclusions: Monozygotic twins can have discordant gonadal dysgenesis even though they are identical genetically.