Characterization of an Early-Onset, Autosomal Recessive, Progressive Retinal Degeneration in Bengal Cats

Invest Ophthalmol Vis Sci. 2015 Aug;56(9):5299-308. doi: 10.1167/iovs.15-16585.

Abstract

Purpose: A form of retinal degeneration suspected to be hereditary was discovered in a family of Bengal cats. A breeding colony was established to characterize disease progression clinically, electrophysiologically, and morphologically, and to investigate the mode of inheritance.

Methods: Affected and related cats were donated by owners for breeding trials and pedigree analysis. Kittens from test and complementation breedings underwent ophthalmic and neuro-ophthalmic examinations and ERG, and globes were evaluated using light microscopy.

Results: Pedigree analysis, along with test and complementation breedings, indicated autosomal recessive inheritance and suggested that this disease is nonallelic to a retinal degeneration found in Persian cats. Mutation analysis confirmed the disease is not caused by CEP290 or CRX variants found predominantly in Abyssinian and Siamese cats. Ophthalmoscopic signs of retinal degeneration were noted at 9 weeks of age and became more noticeable over the next 4 months. Visual deficits were behaviorally evident by 1 year of age. Electroretinogram demonstrated reduced rod and cone function at 7 and 9 weeks of age, respectively. Rod responses were mostly extinguished at 14 weeks of age; cone responses were minimal by 26 weeks. Histologic degeneration was first observed at 8 weeks, evidenced by reduced photoreceptor numbers, then rapid deterioration of the photoreceptor layer and, subsequently, severe outer retinal degeneration.

Conclusions: A recessively inherited primary photoreceptor degeneration was characterized in the Bengal cat. The disease is characterized by early onset, with histologic, ophthalmoscopic, and electrophysiological signs evident by 2 months of age, and rapid progression to blindness.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Neoplasm / genetics*
  • Cat Diseases / diagnosis
  • Cat Diseases / genetics*
  • Cat Diseases / physiopathology
  • Cats
  • DNA / genetics*
  • DNA Mutational Analysis
  • Electroretinography / veterinary
  • Female
  • Genetic Predisposition to Disease
  • Genotype
  • Homeodomain Proteins / genetics*
  • Homeodomain Proteins / metabolism
  • Male
  • Mutation*
  • Neoplasm Proteins / genetics*
  • Ophthalmoscopy / veterinary
  • Pedigree
  • Polymerase Chain Reaction
  • Retinal Cone Photoreceptor Cells / pathology*
  • Retinal Degeneration / diagnosis
  • Retinal Degeneration / genetics*
  • Retinal Degeneration / veterinary
  • Trans-Activators / genetics*
  • Trans-Activators / metabolism

Substances

  • Antigens, Neoplasm
  • Cep290 protein, human
  • Homeodomain Proteins
  • Neoplasm Proteins
  • Trans-Activators
  • cone rod homeobox protein
  • DNA