Categories: Vision / eye phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 609868 (gene) , 604232 (trait)

Single-gene trait/disorder: yes

Mode of inheritance: Autosomal recessive

Disease-related: yes

Key variant known: yes

Year key variant first reported: 2025

Species-specific name: day blindness / retinal degeneration

Inheritance: Pedigree analysis supported an autosomal recessive mode of inheritance (Murgiano et al., 2025).

Molecular basis: Murgiano et al. (2025): "Through GWAS and homozygosity mapping, a large deletion on CFA8:NC_049229.1:g.60,022,583_60,040,453del was found which removes 3’ portions of two different genes, PTPN21 and SPATA7 ... ." The authors propose that the effect on the functional candidate gene SPATA7 is disease causing: "The variant leads to a deletion of the 3’-end of the SPATA7 transcript: XM_038545497.1:r.1,314_1,629delins[g.60,018,954–60,018,990], p.(XP_038401425.1: Asp361GlufsTer2), reducing the predicted protein from 595 to 361 AA."

Clinical features: Murgiano et al. (2025): "Affected dogs had severe vision deficits present at a young age, generally before 2–3 months of age, and characterized by very poor to absent vision under photopic conditions, but with no evidence of photophobia. ... Full-field electroretinography (ERG) was used for objective assessment of retinal function. .... cone ERG responses were absent as early as 7 weeks of age. We also found that as early as 15 weeks of age, rod responses were reduced by ~60–80% in dogs that showed no vascular attenuation or generalized hyperreflectivity ... . Over time, rod responses were further decreased and no longer recordable, and the ERG was considered ‘extinguished’."

Breed: Poodle, Standard (Dog) (VBO_0201056).
Breeds in which the phene or likely causal variants have been documented. If a likely causal variant has been documented, see variant-specific breed information in the variant table. (Breed information may be incomplete).

Associated gene: