Research suggests that this variant is associated with many clinical symptoms associated with brachycephalic conformation associated conditions. Variant may be fixed in some breeds.

Both clinically rare and of complex inheritance. Test is considered poorly correlated with risk for development of DM, and recommendations are to not use the test for breed-wide breeding strategies. While the SOD 1 variant may be commonly found across many breeds, there are few clinical cases observed and confirmed, and in many cases DM has never been observed in the breeds.

Villani et al. (2019) reported the c.619C>T variant to be homozygous in an affected mixed-breed dog of unknown parentage. They also reported a 87kb haplotype including the variant that is shared by this affected dog and the breeds in which this variant has been previously reported. Villani et al. (2019) concluded "that the NCL in all of these dogs stems from the same founding mutation event that may have predated the establishment of the modern dog breeds. If so, the CLN5 nonsence allele is probably segregating in other, as yet unidentified, breeds. Thus, dogs exhibiting similar NCL-like signs should be screened for this CLN5 nonsense allele regardless of breed."

Possibly incorrect mutation for this breed. See cystinuria type II-A

Both clinically rare and of complex inheritance. Test is considered poorly correlated with risk for development of DM, and recommendations are to not use the test for breed-wide breeding strategies. While the SOD 1 variant may be commonly found across many breeds, there are few clinical cases observed and confirmed, and in many cases DM has never been observed in the breeds.

The mutation associated with EIC has been identified in a number of breeds - particularly hunting/working breeds. As the EIC phenotype requires an environmental stimulus in most cases, it should be noted that dogs could be genetically affected for EIC without displaying the condition. It may be valuable to breeders of those breeds where the mutation has been detected to use a genetic test, where breed-specific research is ongoing.