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Persistent Mullerian Duct Syndrome Types I and II; PMDS, OMIM #261550

Persistent Mullerian Duct Syndrome Types I and II; PMDS

OMIM number: 261550

Comments closing date: 27/10/2022

Persistent Müllerian duct syndrome (PMDS) is a disorder of sexual development that affects males. Males with this disorder have normal male external genitalia, though they also have a uterus and fallopian tubes. The uterus and fallopian tubes are derived from a structure called the Müllerian duct during foetal development. The Müllerian duct usually breaks down during early development in males, but it is retained in those with PMDS. Affected individuals have normal male chromosomes (46,XY). PMDS is caused by a mutations in the genes for either anti-Müllerian hormone (AMH) (PMDS type I) or the AMH receptor (AMHR2 gene, PMDS type II). The first noted signs and symptoms in males with PMDS are usually undescended testes (cryptorchidism) or soft out-pouchings in the lower abdomen (inguinal hernias). The uterus and fallopian tubes are typically discovered when surgery is performed to treat these conditions. The testes and female reproductive organs can be located in unusual positions in PMDS. Occasionally, both testes are undescended (bilateral cryptorchidism) and the uterus is in the pelvis. More often, one testis has descended into the scrotum normally, and one has not. Sometimes, the descended testis pulls the fallopian tube and uterus into the track through which it has descended. This creates a condition called hernia uteri inguinalis, a form of inguinal hernia. In other cases, the undescended testis from the other side of the body is also pulled into the same track, forming an inguinal hernia. This condition, called transverse testicular ectopia, is common in people with PMDS. Other effects of PMDS may include the infertility, or blood in the semen (haematospermia). Furthermore, approximately 15% of patients with PMDS develop germ cell tumours of the undescended testis if left untreated. Whilst the genetic condition itself cannot be treated it is possible to address the structural abnormalities with surgery.

Review date: 5 January 2025