Gene mutation linked to rare canine, human eye disorder

OSLO, NORWAY — A gene mutation may cause a naturally occurring, rare eye disease suffered by certain dogs and humans, according to a new study.

Cone-rod dystrophy (CRD) is only known to affect wire-haired Dachshunds, miniature long-haired Dachshunds and Pit Bull Terriers, but also can occur in humans, causing daytime and eventually complete blindness.

Early onset of the retinal degenerative disorder can occur in the wire-haired Dachshund, the study suggests, through a specific variation on chromosome 5, which contains 70 genes. The canine NPHP4 gene was specifically identified as causing CRD in the standard wire-haired Dachshund, but specific genes have not been identified yet in miniature long-haired Dachshunds or Pit Bull Terriers, according to the study, which was done in collaboration with MIT's Broad Institute.

If the mutation is linked to humans suffering CRD, the study indicates it could lead to new treatment methods. The study notes that mutations in the problem-causing gene for the wire-haired Dachshund also has been linked to eye and kidney disease in humans.

The CRD study was funded by the Division of Genetics and the Department of Companion Animal Clinical Sciences at the Norwegian School of Veterinary Science, and jointly undertaken with the Broad Institute of Harvard and MIT, the Center for Human Genetic Research at Massachusetts General Hospital and the Department of Medical Biochemistry and Microbiology at Uppsala University in Sweden. It was published in Genome Research.