OMIA:000881-9685 : Retinal atrophy - Rod-cone dysplasia, CRX related in Felis catus (domestic cat)

In other species: dog

Categories: Vision / eye phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 613829 (trait) , 602225 (gene)

Links to relevant human diseases in MONDO:

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal incomplete dominant

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2010

Species-specific name: Progressive retinal dystrophy/atrophy; Cone-rod dystrophy/dysplasia

Species-specific symbol: Rdy

Inheritance: Occelli et al. (2023) report that " the phenotype of CRXRdy/Rdy cats was more severe compared to CRXRdy/+ cats by several metrics." The mode of inheritance was therefore changed from autosomal dominant to incomplete dominant.

Molecular basis: Menotti-Raymond et al. (2010) provided convincing evidence that this form of retinopathy, so long studied, is the result of a frameshift mutation due to a single base deletion in the cone-rod homeobox-containing gene (CRX).

Clinical features: Clinically, affected kittens with one copy of the disease allele (CRXRdy/+) can be recognised by the age of 4-5 weeks; they have a slower pupillary light reflex and pupil dilation. 6 weeks old kittens may have a pendular nystagmus, and by 7-8 weeks retinal changes can be observed with ophthalmoscopy in the centralis region. Mottling and grey discolouration of the retina will be observed, and these changes extend to the periphery over a few weeks. By 12 weeks, affected kittens have a generalised hyper-reflectivity of the tapetal fundus, mottling and depigmentation of the non-tapetal area and vascular attenuation. Signs of progressive blindness occur in the first 4 months of life. (Narfström et al., 2011) IT thanks DVM student Jaimie McElroy, who provided the basis of this contribution in May 2023.

Pathology: Occelli et al. (2016) provided a comprehensive description of the pathogenesis in cats that are heterzygous for the frameshift variant (CRXRdy/+) and later reported a more severe phenotype in cats homozygous for the variant (CRXRdy/Rdy) (Occelli et al., 2023): "CRXRdy/Rdy cats had high levels of mutant CRX mRNA and protein. The expression of photoreceptor target genes was severely impaired although there were variable effects on the expression of other transcription factors. The photoreceptor cells remained immature and failed to elaborate outer segments consistent with the lack of retinal function. The retinal layers displayed a progressive remodeling with cell loss but maintained overall retinal thickness due to gliosis. Rapid photoreceptor loss largely occurred in the macula-equivalent retinal region. The homozygous cats developed markedly increased ocular globe length."

Breeds: Abyssinian (Cat) (VBO_0100000), Somali (Cat) (VBO_0100229).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
CRX cone-rod homeobox Felis catus E2 NC_058382.1 (9501906..9490608) CRX Homologene, Ensembl , NCBI gene


By default, variants are sorted chronologically by year of publication, to provide a historical perspective. Readers can re-sort on any column by clicking on the column header. Click it again to sort in a descending order. To create a multiple-field sort, hold down Shift while clicking on the second, third etc relevant column headers.

WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.

OMIA Variant ID Breed(s) Variant Phenotype Gene Allele Type of Variant Source of Genetic Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
916 Abyssinian (Cat) Rod-cone dysplasia CRX Rdy deletion, small (<=20) Naturally occurring variant F.catus_Fca126_mat1.0 E2 g.9492897del c.546del p.(P185Lfs*2) XM_045045412.1; XP_044901347.1; published as CRX: n.546delC; in the Felis_catus_9.0 assembly the CRX gene is duplicated and genomic coordinates in this table are given for a more recent reference genome 2010 20053974

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2023). OMIA:000881-9685: Online Mendelian Inheritance in Animals (OMIA) [dataset].


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.

2023 Occelli, L.M., Jones, B.W., Cervantes, T.J., Petersen-Jones, S.M. :
Metabolic changes and retinal remodeling in Heterozygous CRX mutant cats (CRX RDY/+). Exp Eye Res 235:109630, 2023. Pubmed reference: 37625575. DOI: 10.1016/j.exer.2023.109630.
Occelli, L.M., Tran, N.M., Chen, S., Petersen-Jones, S.M. :
Cat LCA-CRX model, homozygous for an antimorphic mutation has a unique phenotype. Transl Vis Sci Technol 12:15, 2023. Pubmed reference: 37351895. DOI: 10.1167/tvst.12.6.15.
2021 Occelli, L.M., Marinho, F., Singh, R.K., Binette, F., Nasonkin, I.O., Petersen-Jones, S.M. :
Subretinal transplantation of human embryonic stem cell-derived retinal tissue in a feline large animal model. J Vis Exp , 2021. Pubmed reference: 34424232. DOI: 10.3791/61683.
2016 Occelli, L.M., Tran, N.M., Narfström, K., Chen, S., Petersen-Jones, S.M. :
CrxRdy cat: A large animal model for CRX-associated leber congenital amaurosis. Invest Ophthalmol Vis Sci 57:3780-92, 2016. Pubmed reference: 27427859. DOI: 10.1167/iovs.16-19444.
2015 Lyons, L.A. :
DNA mutations of the cat: The good, the bad and the ugly. J Feline Med Surg 17:203-19, 2015. Pubmed reference: 25701860. DOI: 10.1177/1098612X15571878.
2013 Narfström, K., Deckman, K.H., Menotti-Raymond, M. :
Cats: a gold mine for ophthalmology. Annu Rev Anim Biosci 1:157-77, 2013. Pubmed reference: 25387015. DOI: 10.1146/annurev-animal-031412-103629.
2011 Narfström, K., Holland Deckman, K., Menotti-Raymond, M. :
The domestic cat as a large animal model for characterization of disease and therapeutic intervention in hereditary retinal blindness. J Ophthalmol 2011:906943, 2011. Pubmed reference: 21584261. DOI: 10.1155/2011/906943.
Narfström, K., Menotti Raymond, M., Seeliger, M. :
Characterization of feline hereditary retinal dystrophies using clinical, functional, structural and molecular genetic studies. Vet Ophthalmol 14 Suppl 1:30-6, 2011. Pubmed reference: 21923821. DOI: 10.1111/j.1463-5224.2011.00915.x.
2010 Menotti-Raymond, M., Deckman, KH., David, VA., Myrkalo, J., O'Brien, SJ., Narfstrom, K. :
Mutation discovered in a feline model of human congenital retinal blinding disease. Invest Ophthalmol Vis Sci 51:2852-2859, 2010. Pubmed reference: 20053974. DOI: 10.1167/iovs.09-4261.
2002 Gould, D.J., Sargan, D.R. :
Autosomal dominant retinal dystrophy (Rdy) in Abyssinian cats: exclusion of PDE6G and ROM1 and likely exclusion of Rhodopsin as candidate genes Animal Genetics 33:436-440, 2002. Pubmed reference: 12464018.
1999 Chong, N.H.V., Alexander, R.A., Barnett, K.C., Bird, A.C., Luthert, P.J. :
An immunohistochemical study of an autosomal dominant feline rod/cone dysplasia (Rdy cats) Experimental Eye Research 68:51-57, 1999. Pubmed reference: 9986741. DOI: 10.1006/exer.1998.0580.
1993 Gorin, M.B., Snyder, S., To, A., Narfstrom, K., Curtis, R. :
The cat RDS transcript: candidate gene analysis and phylogenetic sequence analysis. Mamm Genome 4:544-8, 1993. Pubmed reference: 8118105. DOI: 10.1007/BF00364792.
Narfstrom, K., Ivert, L., Yamamoto, S., Gouras, P. :
Adaptation of rod and cone electroretinograms in the Abyssinian cat hereditary rod-cone degeneration. Clinical Vision Sciences 8:177-185, 1993.
1991 Anderson, R.E., Maude, M.B., Nilsson, S.E., Narfström, K. :
Plasma lipid abnormalities in the abyssinian cat with a hereditary rod-cone degeneration. Exp Eye Res 53:415-7, 1991. Pubmed reference: 1936178. DOI: 10.1016/0014-4835(91)90249-e.
Holmes, N.G., Curtis, R. :
Changes in a photoreceptor polypeptide correlating with an early-onset retinal dystrophy in the cat. Mol Cell Biochem 107:111-7, 1991. Pubmed reference: 1791824. DOI: 10.1007/BF00225514.
Leon, A., Hussain, A.A., Curtis, R. :
Autosomal dominant rod-cone dysplasia in the Rdy cat. 2. Electrophysiological findings. Exp Eye Res 53:489-502, 1991. Pubmed reference: 1936184. DOI: 10.1016/0014-4835(91)90166-c.
1990 Leon, A., Curtis, R. :
Autosomal dominant rod-cone dysplasia in the Rdy cat. 1. Light and electron microscopic findings. Exp Eye Res 51:361-81, 1990. Pubmed reference: 2209749. DOI: 10.1016/0014-4835(90)90149-o.
1987 Curtis, R., Barnett, K.C., Leon, A. :
An early-onset retinal dystrophy with dominant inheritance in the Abyssinian cat. Clinical and pathological findings Investigative Ophthalmology and Visual Science 28:131-139, 1987. Pubmed reference: 3804643.
1985 Barnett, KC., Curtis, R. :
Autosomal dominant progressive retinal atrophy in Abyssinian cats. J Hered 76:168-70, 1985. Pubmed reference: 3998438.

Edit History

  • Created by Frank Nicholas on 08 Apr 2010
  • Changed by Frank Nicholas on 30 Sep 2011
  • Changed by Frank Nicholas on 09 Dec 2011
  • Changed by Frank Nicholas on 22 Mar 2019
  • Changed by Imke Tammen2 on 26 Aug 2021
  • Changed by Imke Tammen2 on 17 Sep 2022
  • Changed by Imke Tammen2 on 07 Jun 2023
  • Changed by Imke Tammen2 on 25 Jun 2023