Progressive Retinal Atrophy, Cone-Rod Dystrophy 2 (PRA-crd2)

Most of canine retinal diseases with known causal mutations are rod-cone degenerations, also known as progressive retinal atrophies (PRAs), characterized by progressive rod-led photoreceptor degenerations that is followed by cone photoreceptor demise. In contrast, cone-rod dystrophies are characterized by the relatively early loss of cone photoreceptors. Crd2-PRA usually affects very young dogs (less than 1-year old) and cause severe photopic and scotopic visual impairment, which can progress to complete blindness in early adulthood. Mutation causing crd2-PRA has been observed in American Pit Bull Terrier dogs. Because American Pit Bull Terrier and American Staffordshire Terrier are closely related breeds and are sometimes crossbreed it is possible that the same mutation also appears in American Staffordshire Terrier.

Inheritance: autosomal recessive

Mutation: IQCB1 gene

Genetic test: The method used for testing is extremely accurate and allows complete differentiation between affected animals, carriers and healthy dogs. Testing can be done at any age.