Affected Gene: CCDC66
Transmission: Autosomal Recessive
Mutation: CanFam3.1 20 g.33717704_33717705insT c.2262_c.2263insA
OMIA Link: 001521-9615

Breeds Recommended for Testing: Portuguese Water Dog

Symptoms:
Portuguese Water Dogs affected by Early-Onset Progressive Retinal Atrophy (EOPRA) show visual deficits, including difficulty following moving objects and walking near stationary objects. In the study by Murgiano et al., 2020, the disease was detected around 2-3 years of age. A characteristic feature of EOPRA, observed in all affected dogs, is a distinct peripapillary ring of hyperreflectivity or peripapillary cone, which progresses to a larger area of hyperreflectivity around the optic disc in advanced stages of the disease.

References:
Murgiano, L., Becker, D., Spector, C., Carlin, K., Santana, E., Niggel, J.K., Jagannathan, V., Leeb, T., Pearce-Kelling, S., Aguirre, G.D., Miyadera, K.
CCDC66 frameshift variant associated with a new form of early-onset progressive retinal atrophy in Portuguese Water Dogs.
Sci Rep 10:21162, 2020. PubMed: 33273526
DOI: 10.1038/s41598-020-77980-5