Purpose: To characterize the electrophysiological and histopathological features of a retinal degenerative disease in a colony of miniature longhaired dachshunds known to have a form of progressive retinal atrophy (PRA).
Methods: Serial electroretinograms were recorded from affected homozygous (n = 36) and heterozygous (n = 15) dogs. Morphologic investigations including immunohistochemistry and lectin histochemistry were performed on selected homozygous animals (n = 15).
Results: Clinical findings included loss of tapetal hyperreflectivity. The mode of inheritance was autosomal recessive. An early dramatic reduction of cone-specific ERG amplitude with a more modest reduction in rod b-wave amplitude was demonstrated. Progressively, rod specific responses diminished until there were no recordable responses to the ERG stimuli at 40 weeks of age. Morphologic changes confirmed early cone inner and outer segment loss. Other abnormalities included opsin mislocalization and outer nuclear layer thinning due to the subsequent loss of rod photoreceptors.
Conclusions: A novel canine cone-rod dystrophy has been identified.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1167/iovs.04-0737 | DOI Listing |
Vet Ophthalmol
October 2024
Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Objective: Cone-rod dystrophy (cord1) is a form of progressive retinal atrophy. It is linked to an RPGRIP1 genetic variant which is the third most common canine disease variant thus far. While the variant affects various breeds, it is highly prevalent in English Springer Spaniels (ESSs).
View Article and Find Full Text PDFCell Death Dis
September 2024
Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.
PRLΔE1, a retina-specific isoform of prolactin, is expressed in multiple and diverse forms of canine inherited retinal degeneration (IRD). We find that while PRLΔE1 expression in rods is not associated with the initial phase of disease characterized by acute photoreceptor cell death, it is associated with the protracted phase of slow cell loss. Restoration of photoreceptors to a healthy state by gene-specific replacement therapy of individual IRDs successfully suppresses PRLΔE1 expression.
View Article and Find Full Text PDFClin Genet
January 2025
Christian-Albrechts-University Kiel, Institute of Biochemistry, Kiel, Germany.
Usher syndrome (USH) is the most common cause of deafblindness. USH is autosomal recessively inherited and characterized by rod-cone dystrophy or retinitis pigmentosa (RP), often accompanied by sensorineural hearing loss. Variants in >15 genes have been identified as causative for clinically and genetically distinct subtypes.
View Article and Find Full Text PDFGenes (Basel)
July 2024
Canine Genetics Centre, Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK.
Progressive retinal atrophies (PRAs) are a genetically heterogeneous group of inherited eye diseases that affect over 100 breeds of dog. The initial clinical sign is visual impairment in scotopic conditions, as a consequence of rod photoreceptor cell degeneration. Photopic vision degeneration then follows, due to progression of the disease to the cone photoreceptors, and ultimately results in complete blindness.
View Article and Find Full Text PDFNat Commun
July 2024
Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, University of California, Irvine, CA, 92697, USA.
Inherited retinopathies are devastating diseases that in most cases lack treatment options. Disease-modifying therapies that mitigate pathophysiology regardless of the underlying genetic lesion are desirable due to the diversity of mutations found in such diseases. We tested a systems pharmacology-based strategy that suppresses intracellular cAMP and Ca2+ activity via G protein-coupled receptor (GPCR) modulation using tamsulosin, metoprolol, and bromocriptine coadministration.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!