Breeds Affected: Miniature Schnauzer
Samples Accepted: Blood, Buccal Swabs
Disease Information: Persistent Müllerian Duct Syndrome (PMDS) is caused by a hormonal failure, which leads to both male and female internal genitalia in affected male dogs. Dogs appear normal externally, although approximately 50% may be unilaterally or bilaterally cryptorchid, and those with at least one descended testicle are fertile. Internally, female organs also exist in affected male dogs, including oviducts, uterus, and cervix.
Inheritance Information: PMDS is autosomal recessive, meaning that animals with two copies of this allele will be affected. Animals with one copy of the gene will be clinically-normal carriers.
The possible genotypes are:
N/N The dog is normal, and cannot produce affected offspring.
N/pmds The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/pmds carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
pmds/pmds The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/pmds carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/pmds x N/N) without any risk of producing affected offspring. The offspring should be tested before breeding to determine if they are carriers or normal.
– Breeding two carriers (N/pmds x N/pmds) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (pmds/pmds) should not be used for breeding.
Test Information: This mutation test identifies a single base pair change in exon 3 of the MISRII gene.
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 Mullerian Duct Syndrome. J Androl 30:46-56, 2009. Pubmed reference: 18723470. DOI: 10.2164/jandrol.108.005736.
Further information is available at the Online Mendelian Inheritance in Animals website