Genetic Factors Associated with Lumbosacral Stenosis in Labrador Retrievers

Lumbosacral stenosis (LS) is a leading cause of low back pain, disability, and early retirement in large-breed working dogs. Lumbosacral stenosis is defined as narrowing of the lumbar and/or sacral spinal canal that results in compression of nerve tissues. Previous studies have established a close genetic similarity between the human and canine genome and have shown that genetic factors are associated with a similar disease in humans – lumbar spinal stenosis. However, studies exploring genetic associations with LS in dogs are currently lacking. Our aim is to identify genetic polymorphisms within the canine exome that are associated with the LS phenotype in a popular dog breed that is predisposed to LS.

Computed tomography (CT) is an established method for diagnosing lumbar spinal stenosis in humans and LS in dogs. We used CT to identify 4 Labrador retrievers positive for LS and 4 Labrador retrievers negative for LS. We isolated genomic DNA (Wizard SV Genomic DNA Purification System, Promega Corp., Madison, WI, USA) from peripheral blood drops collected on FTA cards (Whatman Plc., Maidstone, UK) for all 8 dogs. We will be sequencing the whole exome of these 8 dogs using a whole exome capture kit (Nextera, Illumina, San Diego, CA, USA).  Sequencing data will be analyzed and compared with each other, as well as with the canine reference genome to identify any sequence variation in the exome that might be significantly associated with LS in Labrador retrievers. This is an ongoing project and we expect results by December 2014.