OMIA:000830-9940 : Retinal atrophy, progressive, generic in Ovis aries (sheep)
Categories: Vision / eye phene
Links to MONDO diseases: No links.
Mendelian trait/disorder: unknown
Mode of inheritance: Probably autosomal recessive
Considered a defect: yes
Cross-species summary: Progressive, non-inflammatory degeneration or dysplasia of rods and cones or just of rods, leading to firstly night blindness, and later to blindness during the day.
Species-specific description: Hunt et al. (2022) report a suspected autosomal recessive form of progressive retinal atrophy in Wiltshire sheep.
Inheritance: Hunt et al. (2022) "pedigree analysis suggested an inherited basis for the disease. Mating an affected Wiltshire ram to 2 affected Wiltshire ewes resulted in 6 progeny that all developed retinal degeneration by 2 years of age, while mating of the same affected ram to 6 unaffected ewes resulted in 8 unaffected progeny, consistent with autosomal recessive inheritance."
Mapping: Hunt et al. (2022) "Homozygosity mapping of 5 affected Wiltshire sheep and 1 unaffected Wiltshire sheep using an OvineSNP50 Genotyping BeadChip revealed an identical-by-descent region on chromosome 5, but none of the genes within this region were considered plausible candidate genes. Whole-genome sequencing of 2 affected sheep did not reveal any significant mutations in any of the genes associated with retinitis pigmentosa in humans or progressive retinal atrophy in dogs."
Have human generated variants been created, e.g. through genetic engineering and gene editing
Clinical features: Hunt et al. (2022): "Affected [Wiltshire] sheep developed night blindness between 2 and 3 years of age, which progressed to complete blindness by 4 to 5 years of age. Fundic examination findings included progressive tapetal hyperreflectivity and attenuation of retinal blood vessels."
Pathology: Hunt et al. (2022): "Histologically, the retinas had a selective loss of rod photoreceptors with initial preservation of cone photoreceptors. Retinal degeneration was not accompanied by any other ocular or central nervous system abnormalities ..."
Breeds in which the phene has been documented. For breeds in which a likely causal variant has been documented, see the variant table below
Cite this entry
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.
|2022||Hunt, H., Dittmer, K.E., Garrick, D.J., Fairley, R.A., Heap, S.J., Jolly, R.D. :|
|An inherited night blindness in Wiltshire sheep. Vet Pathol 59:310-318, 2022. Pubmed reference: 34974772. DOI: 10.1177/03009858211067461.|
|1973||Terlecki, S., Young, G.B., Buntain, D. :|
|Absence of simple genetic factors in progressive retinal degeneration (bright blindness) in sheep. Br Vet J 129:xlv-xlviii, 1973. Pubmed reference: 4733764.|
|1972||Watson, W.A., Barnett, K.C., Terlecki, S. :|
|Progressive retinal degeneration (Bright Blindness) in sheep: a review. Vet Rec 91:665-70, 1972. Pubmed reference: 4675711. DOI: 10.1136/vr.91.27.665.|
- Created by Frank Nicholas on 06 Sep 2005
- Changed by Imke Tammen2 on 11 Jan 2022