The Persistent Mullerian Duct Syndrome: A Molecular Approach*

Abstract

A rare form of male pseudohermaphroditism is characterized by the persistence of Muellerian derivatives in phenotypic males. To determine the etiology of this syndrome, we studied the expression of anti-Muellerian hormone (AMH) in six boys, including three brothers, with the persistent Muellerian duct syndrome. All except one presented with an inguinal hernia containing the Muellerian derivatives, and in two boys the hernial sac contained the controlateral testis. AMH was normally expressed in the testicular tissue of two patients, as shown by bioassay of anti-Muellerian activity and immunocytochemistry. The testicular tissue of the other patients had no detectable bioactive or immunoreactive AMH, yet they expressed AMH mRNA with a normal transcription initiation site and in the amount expected for their age. These results prove the heterogeneity of the persistent Muellerian duct syndrome and suggest that it may sometimes involve peripheral insensitivity to AMH.