Persistent Müllerian duct syndrome

Persistent Müllerian duct syndrome, abbreviated PMDS, is the presence of Müllerian duct derivatives, meaning fallopian tubes, a uterus or the upper part of the vagina, in what would otherwise be considered a genetically and physically normal male by typical human standards. In humans it is typically an autosomal recessive congenital disorder, and some consider it a form of pseudohermaphroditism because of the Müllerian derivatives. It can also present in non-human animals. Typical features are undescended testes, known as cryptorchidism, and a small, underdeveloped uterus in an XY infant or adult. The condition is usually caused by a deficiency of fetal anti-Müllerian hormone effect, through mutations of the gene for the hormone or for its receptor, but it may also result from insensitivity of the target organ to the hormone.