Progressive retinal atrophy (PRA, rdAc)
The light-sensing cells of the eye slowly wear out, so a cat sees less well. How badly it affects the Siamese family is not yet settled. In one survey about 1 in 5 Balinese carried the gene; a cat only gets it with two copies.
How it is found: DNA test of the parents with a cheek swab. Two carriers are not mated with each other.






