Cat (Felis catus) — Progressive retinal dystrophy/atrophy; Cone-rod dystrophy/dysplasia (hereditary; OMIA-verified species predisposition)

Cat (Felis catus) — Progressive retinal dystrophy/atrophy; Cone-rod dystrophy/dysplasia (hereditary; OMIA-verified species predisposition)

Source: first-hand OMIA (University of Sydney) species-specific hereditary-disorder record, saved verbatim to source_file; every claim below is a C1 byte-substring of it.

Claims

• Species: Cat (Felis catus)
• Disorder: Progressive retinal dystrophy/atrophy; Cone-rod dystrophy/dysplasia
• Mode of 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.
• Clin feat: 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."

Associated gene(s)

Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.

• Gene: Entrez Gene ID 30205854 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene
• OMIA molecular-genetics note: 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 (omia.variant:916) in the cone-rod homeobox-containing gene (<em>CRX</em>).

Evidence (references)

Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.

• 1987. An early-onset retinal dystrophy with dominant inheritance in the Abyssinian cat. Clinical and pathological findings. Investigative Ophthalmology and Visual Science — PubMed:PMID3804643 — OMIA Phene_Article / Article
• 1990. Autosomal dominant rod-cone dysplasia in the Rdy cat. 1. Light and electron microscopic findings. Exp Eye Res — PubMed:PMID2209749 | DOI:10.1016/0014-4835(90)90149-o — OMIA Phene_Article / Article
• 1991. Changes in a photoreceptor polypeptide correlating with an early-onset retinal dystrophy in the cat. Mol Cell Biochem — PubMed:PMID1791824 | DOI:10.1007/BF00225514 — OMIA Phene_Article / Article
• 1991. Autosomal dominant rod-cone dysplasia in the Rdy cat. 2. Electrophysiological findings. Exp Eye Res — PubMed:PMID1936184 | DOI:10.1016/0014-4835(91)90166-c — OMIA Phene_Article / Article
• 1991. Plasma lipid abnormalities in the abyssinian cat with a hereditary rod-cone degeneration. Exp Eye Res — PubMed:PMID1936178 | DOI:10.1016/0014-4835(91)90249-e — OMIA Phene_Article / Article
• 1993. Adaptation of rod and cone electroretinograms in the Abyssinian cat hereditary rod-cone degeneration. Clinical Vision Sciences — OMIA Phene_Article / Article
• 1993. The cat RDS transcript: candidate gene analysis and phylogenetic sequence analysis. Mamm Genome — PubMed:PMID8118105 | DOI:10.1007/BF00364792 — OMIA Phene_Article / Article
• 1999. An immunohistochemical study of an autosomal dominant feline rod/cone dysplasia (Rdy cats). Experimental Eye Research — PubMed:PMID9986741 | DOI:10.1006/exer.1998.0580 — OMIA Phene_Article / Article
• 2002. Autosomal dominant retinal dystrophy (Rdy) in Abyssinian cats: exclusion of PDE6G and ROM1 and likely exclusion of Rhodopsin as candidate genes. Animal Genetics — PubMed:PMID12464018 — OMIA Phene_Article / Article
• 1985. Autosomal dominant progressive retinal atrophy in Abyssinian cats. J Hered — PubMed:PMID3998438 — OMIA Phene_Article / Article
• 2010. Mutation discovered in a feline model of human congenital retinal blinding disease. Invest Ophthalmol Vis Sci — PubMed:PMID20053974 | DOI:10.1167/iovs.09-4261 — OMIA Phene_Article / Article
• 2011. The domestic cat as a large animal model for characterization of disease and therapeutic intervention in hereditary retinal blindness. J Ophthalmol — PubMed:PMID21584261 | DOI:10.1155/2011/906943 — OMIA Phene_Article / Article
• (9 additional references in OMIA)

Comparative medicine (human OMIM)

Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.

• OMIM:613829 (type: trait) — OMIA Group_OMIM (via OMIA_ID)
• OMIM:602225 (type: gene) — OMIA Group_OMIM (via OMIA_ID)