Several hundred disease-causing mutations are currently known in domestic dogs. Breeding management is therefore required to minimize their spread. Recently, genetic methods such as direct-to-consumer testing have gained popularity; however, their effects on dog populations are unclear. 

A variant in the RPGRIP1 gene is a causative element associated with cone-rod dysplasia 1 (cord1) and progressive retinal atrophy (PRA) in dogs, notably purebred Miniature Dachshunds (DHMs).

Here, we aimed to evaluate the influence of genetic testing on the frequency of mutations responsible for canine PRA and assess the changes in the genetic structure of a DHMs population from Japan.

To evaluate the influence of genetic testing on the frequency of mutations causing canine degenerative myelopathy and changes to genetic structure in the Pembroke Welsh corgi population from Japan, 117 dogs were genotyped.

Weir and Cockerham population differentiation (FST) based on genome-wide single-nucleotide polymorphism (SNP) detected the SNP with the highest FST located in the intron of SOD1 adjacent to the c.118G>A mutation, supporting a selection signature on SOD1. Further genome-wide SNP analyses revealed no obvious changes in inbreeding levels between the 2019 and 2022 populations.

Our study highlights that genetic testing can help inform improved mating choices in breeding programs to reduce the frequency of risk variants and avoid inbreeding.