Progressive Retinal Atrophy (Discovered in the Golden Retriever; GR_PRA2)
Progressive Retinal Atrophy (Discovered in the Golden Retriever; GR_PRA2). Autosomal recessive. Observed in 7 of 266 breeds tested in the Sniff Atlas, with measured carrier frequencies drawn from 242,662 dogs (Donner 2023). Per-dog phenotype outcome depends on penetrance, modifiers, and environment; the carrier frequencies below describe variant prevalence, not disease incidence.
- OMIA identifier
- OMIA:001984-9615
- InheritanceInheritance patternWhat it isHow the condition is passed down: recessive (two copies needed), dominant (one copy), or more complex.For your dogRecessive means a single-copy carrier is usually healthy but can still pass it on.PreciselyThe documented mode of Mendelian transmission (autosomal recessive or dominant, X-linked, etc.) per OMIA.OMIA · documented
- Autosomal recessive
- Source dataset
- Sniff Atlas v1.0.1 / DOI
A model of human retinitis pigmentosa 51
This is the canine counterpart of retinitis pigmentosa 51 in people. That makes affected dogs a naturally-occurring model of the human disease, and it is part of why studying dogs moves medicine forward for everyone. It does not mean your dog has the human disease. It means the two share an underlying biology.
In people, the disease is described as: Any retinitis pigmentosa in which the cause of the disease is a mutation in the TTC8 gene.
In humans it is also called: RP51, retinitis pigmentosa caused by mutation in TTC8, retinitis pigmentosa type 51, TTC8 retinitis pigmentosa.
Mapped from OMIA via the human disease's OMIM entry to the Mondo Disease Ontology (Monarch Initiative, CC-BY 4.0). Closely related human conditions exist for this gene. Sniff renders this as a model-of link; the canine disease remains the subject of this page.
From OMIA's curated record
Documented in OMIA (Online Mendelian Inheritance in Animals). This describes the disease as recorded in the published literature, not a prediction for any individual dog. As of 2026-06-03.
Summary
Clinical features
Molecular genetics
Human analog
OMIA links this condition to its human counterpart in OMIM (Mendelian Inheritance in Man), the place to read across to the deeper human literature for the same biology.
Source: OMIA (Nicholas, Tammen & the Sydney Informatics Hub), entry OMIA:001984-9615, doi:10.25910/2AMR-PV70 (CC-BY 4.0).
How it presents
Catalogued in the Mondo disease ontology (the cross-species disease identity used by the Monarch Initiative) as retinitis pigmentosa 51 (MONDO:0013274), Bardet-Biedl syndrome 8 (MONDO:0014436).
Phenotype terms: Human Phenotype Ontology + Mammalian Phenotype Ontology; disease terms: Mondo (Monarch Initiative). Cross-references curated by OMIA (doi:10.25910/2AMR-PV70, CC-BY 4.0).
Published references
The peer-reviewed papers behind this disease, curated by OMIA. Starred entries are OMIA-designated landmark papers. Showing 6 of 9.
- Consensus guidelines for nomenclature of companion animal inherited retinal disorders. · Vet Ophthalmol · 2024 · PMID 38334230
- Genome sequencing of 2000 canids by the Dog10K consortium advances the understanding of demography, genome function and architecture. · Genome Biol · 2023 · PMID 37582787
- Allele frequency of SLC4A3 (PRA1), TTC8 (PRA2), and PRA-prcd mutations in golden retrievers in Brazil. · Front Vet Sci · 2022 · PMID 36325094
- The Blue Book: Ocular disorders presumed to be inherited in purebred dogs. 13th Edition · https://ofa.org/wp-content/uploads/2022/10/ACVO-Blue-Book-2021.pdf · 2021
- Deletion in the Bardet-Biedl syndrome gene TTC8 results in a syndromic retinal degeneration in dogs. · Genes (Basel) · 2020 · PMID 32962042
References curated by OMIA (Nicholas, Tammen & the Sydney Informatics Hub), doi:10.25910/2AMR-PV70 (CC-BY 4.0). Full list at the OMIA entry.
Set each parent's status for Progressive Retinal Atrophy (Discovered in the Golden Retriever; GR_PRA2) and see the odds for their puppies. Single recessive variant, exact Mendelian math.
These are the genetic odds for one known variant, not a promise: a real litter varies around them, and penetrance or other genes can change whether the condition ever appears. Use it to avoid pairing two carriers and to keep a line healthy, not to engineer a dog. Inheritance mode per OMIA.
See what Progressive Retinal Atrophy (Discovered in the Golden Retriever; GR_PRA2) looks like in your dog's breed.
Top 7 well-sampled breeds (n ≥ 50)
Maximum carrier frequencyCarrier frequencyWhat it isHow many dogs in a breed carry one copy of a disease variant, usually without being affected themselves.For your dogA carrier is typically healthy. For most recessive conditions a dog needs two copies to be at risk.PreciselyThe proportion of a population carrying at least one copy of the variant allele. Population prevalence, not disease incidence.Sniff Atlas (Donner 2023) · measured per breed across variants in the Donner 2023 cohort, with Wilson 95% confidence intervalsWilson 95% confidence intervalWhat it isThe range the true frequency is probably in. A wide range means we are less sure, usually because few dogs were tested.For your dogTrust tight ranges; treat wide ones as rough estimates.PreciselyA binomial-proportion confidence interval (Wilson score, 95%) that stays reliable at small sample sizes.Sniff Atlas methodology · statistical. The list below is split into well-sampled breeds (n ≥ 50 tested) and small-sample breeds (n < 50, where the Wilson CI typically spans more than 20 percentage points and frequencies should not be compared directly to the well-sampled entries). Frequencies are population-level, not per-litter or per-line.
▸ Full table with Wilson 95% confidence intervals
| Breed | Carrier frequency | n tested |
|---|---|---|
| Golden Retriever | 2.8% | 12,881 |
| Labrador Retriever | 0.91% | 16,856 |
| Poodle Standard | <0.1% | 4,203 |
| Akita | <0.1% | 992 |
| Poodle Miniature | <0.1% | 3,554 |
| American Staffordshire Terrier | <0.1% | 42,793 |
| Bulldog Standard | <0.1% | 4,816 |
259 additional breeds in the Donner 2023 cohort were tested but showed no carriers.
Scope
This record carries the breed-level carrier frequencies from the Donner 2023 cohort. Penetrance data (the fraction of at-risk dogs that develop the phenotype) is not yet quantified for this disease in the Sniff Atlas v1.0.1. The OMIA entry is the authoritative reference for the clinical phenotype, inheritance pattern, and gene assignment.
Predicted disease relevance at the per-dog level is UNPROVEN. The carrier frequency is measured; phenotype outcome depends on penetrance, environment, and modifier loci. Consult a veterinarian for clinical interpretation.
Citations
If you use this record in published work, cite the Sniff Atlas (the published dataset that carries the breed-level carrier frequencies) and the upstream sources:
- Sniff Atlas v1.0.1 for the per-breed carrier frequencies:
Gehring, M. (2026). Sniff Atlas v1.0.1. Zenodo. https://doi.org/10.5281/zenodo.20566358. CC-BY 4.0.
- OMIA for the disease definition, inheritance, and gene assignment:
Nicholas, F. W., & Tammen, I. (2024). OMIA. Sydney Informatics Hub, The University of Sydney. https://doi.org/10.25910/2AMR-PV70. Entry: OMIA:001984-9615.
- Donner et al. 2023 for the breed × variant carrier-frequency cohort:
Donner, J., Freyer, J., Davison, S., Anderson, H., Blades, M., Honkanen, L., et al. (2023). Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs. PLOS Genetics, 19(2), e1010651. https://doi.org/10.1371/journal.pgen.1010651.
Full citation formats (BibTeX, RIS, CITATION.cff) at sniff.world/cite.
Related
- Sniff Atlas v1.0.1, the source dataset for these frequencies.
- Browse breeds, per-breed Mendelian profiles, including this disease in context.
- OMIA entry OMIA:001984-9615, authoritative clinical reference.
- About OMIA, the catalogue this record comes from, and how Sniff uses it.