Identification of DNA Marker(s) for Cataracts in Purebred Dogs, with Emphasis on the Breeds Alaskan Malamute, Siberian Husky, and Samoyed
Dr. Vilma Yuzbasiyan-Gurkan, PhD, Michigan State University
The AKCCHF funded Dr. Vilma Yuzbasiyan-Gurkan, Dr. David Ramsey and Dr. Simon Petersen-Jones at Michigan State University to do a study entitled: Identification of DNA Marker(s) for Cataracts in Purebred Dogs, with Emphasis on the Breeds Alaskan Malamute, Siberian Husky and Samoyed in 1998. This study was completed in late 2001. The objectives were to collect DNA, clinical information and pedigrees from representatives of the three target breeds and then to evaluate mode of inheritance and penetrance by age and clinical outcome. They planned to evaluate linkage of microsatellite markers distributed throughout the canine genome. If linked markers could be identified they would map them on the available reference pedigrees. They hoped to be able to evaluate candidate genes by sequencing the DNA of the parallel canine gene.
Their results support an autosomal recessive mode of inheritance in all three breeds, indicating that affected dogs must receive a gene from each parent. Their data supports a ‘founder effect’ for cataracts in each breed. To try to find the genetic marker for the disease, researchers did a genome-wide linkage analysis with microsatellite markers in each breed. This work has eliminated large portions of the genome for harboring the causative gene. They believe that they were able to identify one marker that is associated with juvenile cataracts in one extensive Samoyed pedigree. Further studies that the group was able to perform did not allow identification of any specific gene as the likely candidate for cataracts in our breed.