OMIA 000830-9940 : Progressive retinal atrophy in Ovis aries

In other species: dog , domestic cat

Possibly relevant human trait(s) and/or gene(s)s (MIM numbers): 613767 (trait) , 600724 (gene)

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."

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 ..."

Breed: Wiltshire.

References


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 :3009858211067461, 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.

Edit History


  • Created by Frank Nicholas on 06 Sep 2005
  • Changed by Imke Tammen2 on 11 Jan 2022