Unexpected finding of an intact distal vagina in an infant with mixed gonadal dysgenesis.

Mixed gonadal dysgenesis (MGD) is a form of sex chromosome disorder of sex development with large phenotypic variability. Patients with MGD typically have asymmetric and ambiguous genitalia with a combination of Müllerian and Wolffian duct derivatives. Prenatal androgen exposure results in variable degrees of phallic enlargement and a urogenital sinus. Here, we report an infant with ambiguous genitalia due to MGD. Despite marked evidence of prenatal androgen exposure, there was a completely intact distal vagina.