Progressive rod-cone degeneration (PRCD) in selected dog breeds and variability in its phenotypic expression

摘要

Progressive rod-cone degeneration (PRCD) is a late onset autosomal photoreceptor degeneration found in canines PRCD in canines is homologous to one form of retinitis pigmentosa (RP) found in humans and displays phenotypic similarity as well as havingthe identical causative mutation. The PRCD gene was mapped to the centromeric region of canine chromosome 9 (CFA9). We report here a population study of 699 dogs of the following breeds and the following frequencies of the disease-causing mutation: American Cocker Spaniel (0.09), English Cocker Spaniel (0.34), English Springer Spaniel (0.00), Welsh Springer Spaniel (0.00), Flat Coated Retriever (0 00) Golden Retriever (0.00), Chesapeake Bay Retriever (0.14), Nova Scotia Duck Tolling Retriever (0.44), Labrador Retriever (0 07), Poodle Toy (0.45), Poodle Miniature (0.20), Poodle Medium (0.05), Poodle Standard (0.00), Portuguese Water Dog (0.33), Chinese Crested Dog (0.02), Shipperke (0.06), and Australian Cattle Dog (0.00). The disease results in complete blindness in the affected individual in almost every case. The time of onset and disease progression varies between dog breeds as well as between individuals. A modifier gene is likely to segregate in genomic proximity to the PRCD gene and may influence phenotypic expression.