Irish Setter PRA Type 1 (PRA-RCD1)
Progressive retinal atrophy (PRA) in Irish Setters is an early onset inherited eye disease and can be due to more than a single mutation. One form of PRA in Irish Setters is referred to as Rod-Cone Dysplasia Type 1 (PRA-RCD1) and occurs as a result of degeneration of both rod and cone cells of the retina which are important for vision in dim and bright light. Symptoms can be recognized as early as a few weeks of age and progressive degeneration can continue for up to a year. The first signs of the disease typically present around 1 month of age with vision loss in dim light also known as night blindness. Dogs will typically show complete loss of night vision by about 5 months and difficulty with vision in bright light. Although there can be variation in disease progression, most dogs typically exhibit a rapid progression with total loss of sight by approximately 1 year of age.
- Irish Setter
A (CLEAR/NORMAL): These dogs have two copies of the normal gene and will neither develop Irish Setter PRA Type 1 nor pass this mutation to their offspring.
B (CARRIER/NOT AFFECTED): These dogs have one copy of the normal gene and one copy of the mutation associated with this disease. They will not develop Irish Setter PRA Type 1 and will, if bred, pass the mutation to 50% of its offspring, on average.
C (AT RISK/AFFECTED): These dogs have two copies of the mutation associated with Irish Setter PRA Type 1 which can result in reduced vision and total loss of sight.