Progressive retinal atrophy - type A

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Progressive retinal atrophy type A is an autosomal-recessive genetic disease characterised by degeneration of the photoreceptor cells in the retina, eventually leading to complete blindness[1].

This genetic disease has been reported in the Miniature Schnauzer.

Most type A PRA cases are clinically indistinguishable from other forms of PRA.

Type A PRA it is usually not seen until 2 - 5 years of age. Type A PRA is a difficult form of retinal atrophy as it can be partially dominant; some carrier animals appear partially affected when examined clinically. Disorientation is a common initial symptom of PRA, particularly at night due to the degeneration of the light sensitive rods specializing in dim light perception.

Initial night blindness in most cases will progress slowly to day blindness also as the cones in the eye that respond to bright light are progressively damaged.

A breed-specific PCR test is available for testing for this condition.

There is no known treatment for this condition and severely affected individual dogs often remain blind.

References

  1. Petit L et al (2012) Restoration of Vision in the pde6β-deficient Dog, a Large Animal Model of Rod-cone Dystrophy. Mol Ther 20(11):2019-2030