Rod-Cone Dysplasia 1 (Discovered in the Irish Setter; rcd1)
Rod-Cone Dysplasia 1 (Discovered in the Irish Setter; rcd1). Autosomal recessive. Observed in 3 of 266 breeds tested in the Sniff Atlas, with measured carrier frequencies drawn from 242,664 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:000882-9615
- 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 40
Dogs with this condition carry a change in PDE6B. In people, changes in the same gene cause retinitis pigmentosa 40. 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 PDE6B gene.
In humans it is also called: RP40, PDE6B retinitis pigmentosa, retinitis pigmentosa caused by mutation in PDE6B, retinitis pigmentosa type 40, retinitis pigmentosa-40.
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
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:000882-9615, 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 33.
- Consensus guidelines for nomenclature of companion animal inherited retinal disorders. · Vet Ophthalmol · 2024 · PMID 38334230
- Altered transsulfuration pathway enzymes and redox homeostasis in inherited retinal degenerative diseases. · Exp Eye Res · 2022 · PMID 34954206
- Restoration of vision and retinal responses after adeno-associated virus-mediated optogenetic therapy in blind dogs. · Transl Vis Sci Technol · 2022 · PMID 35604672
- 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
- Short prolactin isoforms are expressed in photoreceptors of canine retinas undergoing retinal degeneration. · Sci Rep · 2021 · PMID 33432105
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 1 (Discovered in the Irish Setter; rcd1) 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 1 (Discovered in the Irish Setter; rcd1) looks like in your dog's breed.
Top 3 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 |
|---|---|---|
| Irish Setter | 1.2% | 83 |
| Siberian Husky | <0.1% | 9,034 |
| Labrador Retriever | <0.1% | 16,856 |
263 additional breeds in the Donner 2023 cohort were tested but showed no carriers.
From genotype to phenotype
Carrier status is not the same as disease status. Penetrance is the fraction of at-risk dogs that develop the phenotype. The Donner 2023 S4 table tracks this for 1 variant(s) underlying this disease in the cohort.
- At-risk dogs evaluated
- 1
- Phenotype confirmed
- 0
- Penetrance range
- not yet quantifiable
Fewer than 20 at-risk dogs evaluated; too few to state a penetrance figure.
Predicted disease relevance at the per-dog level is UNPROVEN. The carrier frequency is measured; phenotype outcome is governed by 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:000882-9615.
- 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:000882-9615, authoritative clinical reference.
- About OMIA, the catalogue this record comes from, and how Sniff uses it.