Genetic basis of Progressive Retinal Atrophy, Cone-rod Dystrophy in Dachshunds - a
recessive disorder caused by a 180-bp deletion of exon/intron 5 of the NPHP4 gene.
The NPHP4 gene encodes the protein nephrocystin-4, which is crucial for renal tubular
development, function, and acting as part of a ciliary transition zone complex. The
mutation identified in this gene is associated with Retinal atrophy in Dachshunds.
This disorder is inherited in an autosomal recessive manner: affected dogs have two
copies of the mutated gene; carriers have one copy and show no disease but can pass
the mutation to offspring.
Genetic testing using cheek swabs or blood samples can identify clear, carrier, and
affected dogs.
Pathophysiology - The mutation disrupts the function of the NPHP4 protein, essential
for retinal health.
Complications - Affected dogs display day blindness.
Why This Matters to Breeders and Vets - For breeders, knowledge of carrier status is
crucial to avoid producing affected puppies by preventing carrier-to-carrier matings.
For veterinarians, understanding and diagnosing helps in advising owners about care
and management of affected dogs.
Genetic testing facilitates accurate diagnosis and informed breeding decisions to
reduce incidence in the population.
Maintaining breed health and avoiding production of affected dogs improves welfare
and breed quality.
Summary - Progressive Retinal Atrophy, Cone-rod Dystrophy (Dachshund type) is an
autosomal recessive genetic disorder caused by a mutation in the NPHP4 gene.
Affected Dachshunds experience retinal atrophy resulting in day blindness.
Genetic testing is key for diagnosis and to guide breeders in avoiding affected offspring,
thereby improving health and welfare in the breed.
Recommended Breeding
Avoid carrier × carrier matings which have a 25% chance of producing affected puppies.
Breed carriers only to genetically clear (non-carrier) dogs to prevent affected offspring
but some puppies will be carriers.
Routine genetic screening of breeding stock in Dachshunds is recommended to identify
carriers and guide responsible breeding.
Breed clubs and veterinary genetics organisations may provide breeding guidelines to
help reduce and eventually eliminate Retinal Atrophy in Dachshunds while maintaining
genetic diversity.