Persistent Mullerian Duct Syndrome (PMDS)
Persistent Mullerian Duct Syndrome (PMDS) is a sexual development disorder affecting Miniature Schnauzers in which parts of the female reproductive tract develop in male dogs. Approximately half of the affected dogs will develop normal testes and retain fertility but will have internal remnants of female reproductive organs. The other half of affected dogs will suffer from cryptorchidism also known as undescended testicles. They will lack fertility and potentially suffer from an increased risk of testicular tumors and small testes. Some of these dogs will exhibit normal external genitalia making it easy to misdiagnosis PMDS as the cause of cryptorchidism. Male dogs that suffer from PMDS may require a hysterectomy if the uterus becomes infected. Female dogs are not affected by this disease and will have normal internal and external female anatomy.
Reading Your Results
These dogs have two copies of the normal gene and will neither develop Persistent Mullerian Duct Syndrome nor pass this mutation to their offspring.
B. (CARRIER/NOT AFFECTED):
These dogs have one copy of the normal gene and one copy of the mutation associated with this disease. They will not develop Persistent Mullerian Duct Syndrome but will, if bred, pass the mutation to 50% of its offspring, on average.
C. (AT RISK/AFFECTED):
These dogs have two copies of the mutation associated with Persistent Mullerian Duct Syndrome and are likely to develop cryptorchidism and female reproductive tract features in males.
Wu X, Wan S, Pujar S, Haskins ME, Schlafer DH, Lee MM, Meyers-Wallen VN. A single base pair mutation encoding a premature stop codon in the MIS type II receptor is responsible for canine persistent Müllerian duct syndrome. J Androl. 2009 Jan-Feb; 30(1):46-56. [PubMed: 18723470]