Analysis of a deletion in the nephronophthisis 4 gene in different dog breeds.

Cone-rod dystrophy is a progressive inherited retinal degenerative disorder that occurs in humans and dogs. The deletion in the nephronophthisis 4 (NPHP4) gene was established as a causative mutation in standard wire-haired Dachshunds. We analyzed all varieties of Dachshunds from the Czech Republic and five other dog breeds and found that the deletion in the NPHP4 (in heterozygous state) is present not only in standard-, but also in miniature wire-haired Dachshunds, but not in other varieties of Dachshunds or in other breeds.