Rod-Cone Dysplasia 3 (Discovered in the Cardigan Welsh Corgi; rcd3)
Rod-Cone Dysplasia 3 (Discovered in the Cardigan Welsh Corgi; rcd3). Autosomal recessive. Observed in 5 of 266 breeds tested in the Sniff Atlas, with measured carrier frequencies drawn from 242,630 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:001314-9615
- 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 43
Dogs with this condition carry a change in PDE6A. In people, changes in the same gene cause retinitis pigmentosa 43. 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 PDE6A gene.
In humans it is also called: RP43, PDE6A retinitis pigmentosa, retinitis pigmentosa caused by mutation in PDE6A, retinitis pigmentosa type 43.
Mapped from OMIA via the human disease's OMIM entry to the Mondo Disease Ontology (Monarch Initiative, CC-BY 4.0). 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
Molecular genetics
History
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:001314-9615, 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 43 (MONDO:0013437).
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 16.
- ★Genetic panel screening of nearly 100 mutations reveals new insights into the breed distribution of risk variants for canine hereditary disorders. · PLoS One · 2016 · PMID 27525650
Why is this an OMIA Landmark paper? It is "the first large scale report of DNA panel screening across purebred dogs to date", involving the genotyping of 6,788 dogs from 233 breeds for 93 disease-implicated variants across 80 single-locus disorders, providing a very informative "snapshot" of the distribution and frequency of these variants. Importantly, the results indicated "15 risk variants in a total of 34 breeds in which their presence was previously undocumented", which will be very helpful in the provision of genetic counselling in those breeds. The detection of some of these latter variants led to "plausible molecular explanations" for disorders in some breeds.
- Analysis of selected eye disorders in a group of predisposed breeds of dogs: Molecular diagnostics of Collie eye anomaly and progressive retinal atrophy. · Genes (Basel) · 2025 · PMID 40428296
- Gene therapy advances using canine and feline animal models of inherited retinal degeneration. · Eye (Lond) · 2025 · PMID 40461693
- 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
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 Rod-Cone Dysplasia 3 (Discovered in the Cardigan Welsh Corgi; rcd3) 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 Rod-Cone Dysplasia 3 (Discovered in the Cardigan Welsh Corgi; rcd3) looks like in your dog's breed.
Top 5 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 |
|---|---|---|
| Chinese Crested | 1.5% | 204 |
| Cardigan Welsh Corgi | 1.2% | 125 |
| Pomeranian | 0.87% | 5,293 |
| Chihuahua | <0.1% | 4,273 |
| Poodle Standard | <0.1% | 4,203 |
261 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:001314-9615.
- 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:001314-9615, authoritative clinical reference.
- About OMIA, the catalogue this record comes from, and how Sniff uses it.