[From embryogenesis to female phenotype in subjects with XY karyotype]

On the basis of the findings of their investigation of the embryogenesis of the female genital tract, the authors advance a hypothesis concerning the origin of ambiguities between the genetic sex and the gonophoric sex which determine primary sexual characteristics observed in Morris' syndrome and in gonadoblastoma. According to the authors, in gonadoblastoma there is dysgenesis or even agenesis of the gonads, with a total absence of Sertoli cells and, therefore, no secretion of anti-Müller substance and this explains the development of the Müller canals into uterus and Fallopian tubes and the presence of a vagina in an XY subject. In the syndrome of the feminizing testis, XY subjects have testes containing Sertoli cells which have produced anti-Müller substance. However, the initiation of the production of this substance is delayed and it is this delay which has permitted the tendency towards feminization of the uro-genital sinus with the formation of a vagina. The authors thus refute the theory which holds that the Müller cells are involved in the genesis of the vagina.