Progressive Retinal Atrophy Rod-Cone Dysplasia 3 (PRA-RCD3)
Progressive Retinal Atrophy, Rod-Cone Dysplasia 3, PRA-rcd3
Progressive Retinal Atrophy (PRA) is a category of different progressive conditions leading to retinal atrophy and potential blindness. Cardigan Welsh Corgi, Pembroke Welsh Corgi, Chinese Crested, and Pomeranian breeds can be affected by a particular type of PRA known as PRA-RCD3. Disease symptoms can present as early as 1 year old or earlier and are typically observed during an eye exam. The rod cells of the eye which are responsible for vision in low light (night time) show gradual deterioration and the dog rapidly exhibits “night blindness” which is typically seen as a gradual inability for the dog to go outside at night due to loss of night vision. At approximately 2-3 years of age, the dog’s cone cells begin to degenerate. The disease continues to progress leading to a loss of color vision and vision in bright light and eventually results in complete blindness.
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These dogs have two copies of the normal gene and will neither develop Progressive Retinal Atrophy due to the PRA-RCD3 mutation 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 Progressive Retinal Atrophy due to the PRA-RCD3 mutation but will, if bred, pass the mutation to 50% of its offspring, on average.
C. (AT RISK/AFFECTED):
These dogs have two copies of the PRA-RCD3 mutation associated with Progressive Retinal Atrophy which results in night blindness followed by loss of color vision in bright light and eventual complete blindness.
Chr4:59145361 (CanFam3): 1 Bp Deletion (Del A)
Petersen-Jones SM, Entz DD, Sargan DR. cGMP phosphodiesterase-alpha mutation causes progressive retinal atrophy in the Cardigan Welsh corgi dog. Invest Ophthalmol Vis Sci. 1999 Jul; 40(8):1637-44. [PubMed: 10393029]