Official Kennel Club DNA Testing Scheme
Progressive Retinal Atrophy (prcd-PRA)
PRA is a disease that causes the retina of the eye to degenerate slowly over time, the result is declining vision and eventual blindness. Progressive rod-cone degeneration (prcd) is just one type of PRA, it occurs as a result of degeneration of the rod and cone photoreceptor cells of the Retina. Most affected dogs will show no signs of vision loss until around 3 to 5 years of age or later. The rod type cells are affected first and affected dogs will initially have vision deficits in dim light (night blindness) and loss of peripheral vision. Over time affected dogs continue to lose night vision and begin to show visual deficits in bright light. This type of PRA was originally discoverd in black Giant Schnauzers in America. The causal mutation was found to be the same as a few other breeds, for which a DNA test already existed via Optigen. Since then carriers of prcd-PRA are known to have been imported into the UK. According to the Orthopaedic Foundation For Animals, their statistics show a 7.1% carrier rate for prcd-PRA in the Giant Schnauzer.
The mode of inheritance is autosomal recessive, which means a dog will only be affected if they have 2 copies of the recessive gene, one from the sire and one from the dam. The result of the DNA test will be either clear, carrier or affected. See Breeding from a DNA Tested Dog for further information regarding the result and breeding advice.
A DNA test for prcd-PRA is available via:
Part of the Kennel Club CombiBreed DNA Package
MyDogDNA partnership with Optigen – available as an add-on option to a base panel of other tests.
This DNA test can be completed by simple cheek swabs posted back to the appropriate lab, see the test providers websites for more information.
Dilated Cardiomyopathy (DCM)
This type of DCM is a serious and most often fatal heart condition diagnosed in young Giant Schnauzers, causing swelling of the lower chambers of the heart (ventricles). The heart’s ability to pump blood is reduced since the heart becomes enlarged, and can no longer beat effectively. Genetic analysis of 3 affected UK pepper/salt Giant Schnauzer littermates from European breeding, along with their close relatives, took place at the University of Missouri during 2014. Results from this research found the same mutation as presented in Standard Schnauzers.
The mode of inheritance is autosomal recessive, which means a dog will only be affected if they have 2 copies of the recessive gene, one from the sire and one from the dam. The result of the DNA test will be either clear, carrier or affected. See Breeding from a DNA Tested Dog for further information regarding the result and breeding advice.
Giant Schnauzer breeders may order the DCM test via the following:
Part of the Kennel Club CombiBreed DNA Package
Orthopaedic Foundation for Animals (OFA)
Statistics available via OFA show an incidence rate of 6.8% carriers in the Giant Schnauzer. More information about DCM can be found on the link above.
Generalised Progressive Retinal Atrophy (GPRA) – PRA5
Another type of the degenerative blinding eye condition, PRA, was discovered in a litter of UK bred Giant Schnauzers during 2016. Three affected littermates of European pepper/salt breeding were identified as affected, and subsequent testing with the existing prcd-PRA DNA test, described above, proved that this was a different type. Samples from the affected dogs and close relatives were sent to the Animal Health Trust where a whole genome sequencing approach was used to identify the mutation (NECAP1) for this novel type of PRA. An additional 309 Giant Schnauzers were involved in the research from 3 different cohorts in the UK, Finland and Switzerland. Of these additional research dogs, a further 9 were found to be carriers, and carriers were seen in both black and pepper/salt Giants. The AHT estimate that approximately 1 in 4715 giant schnauzers will be homozygous for this mutation, and 1 in 35 dogs (2.9%) will be carriers. The full research article can be found on the following link: Whole Genome Sequencing of Giant Schnauzer Dogs with Progressive Retinal Atrophy Establishes NECAP1 as a Novel Candidate Gene for Retinal Degeneration
The mode of inheritance is autosomal recessive, which means a dog will only be affected if they have 2 copies of the recessive gene, one from the sire and one from the dam. The result of the DNA test will be either clear, carrier or affected. See Breeding from a DNA Tested Dog for further information regarding the result and breeding advice.
The DNA test was originally available via the AHT and is now provided by Animal Diagnostics and Laboklin as well as the Kennel Club CombiBreed package:
Part of the Kennel Club CombiBreed DNA Package