Progressive Retinal Atrophy (IG1)
Progressive retinal atrophy (PRA) is a genetic disease characterized by progressive degeneration of the photoreceptors in the retina that leads to blindness. There is no treatment for PRA.
The incidence of PRA in Italian Greyhounds is 2-4% and it is usually diagnosed at 1 to 14 years of age (6.5 years average). Recent discoveries by UC Davis canine researchers Dr. Niels Pedersen and Hongwei Liu identified mutations in 5 loci that are associated with susceptibility to 90% of the PRA in Italian Greyhounds. This form of PRA, designated as PRA-IG1, can be subdivided into 3 subtypes (PRA-IG1a, 1b, and 1c) based on risk genotypes.
PRA-IG1a is associated with allele (a) at the major locus that is solely responsible for blindness when in a homozygous state (aa). PRA-IG1b occurs when this allele is in the heterozygous state (Aa) and associated with alleles b and c. PRA-IG1c involves alleles a, d and e loci in various combinations. PRA-IG1a comprises 42% of PRA cases in the breed, PRA-IG1b 29%, and PRA-IG1c 20%.
Examples of Test Results :
- AA bb cc DD EE
- AA Bb CC DD Ee
- AA Bb Cc DD Ee
- AA BB Cc DD Ee
Loading