Background: Whole genome sequencing (WGS) is an underutilized tool for diagnosis of suspected genetic diseases, particularly in canines.

Objective: Utilize genetic analysis following WGS of an affected canine patient to pinpoint a potential genetic basis for disease.

Animals: One client-owned, ten-month-old Golden Retriever presenting with signs of possible connective tissue disorder. Blood and DNA samples from a non-affected German Shepherd-Beagle mix and seven Golden Retrievers previously tested for ichthyosis were used as controls.

Methods: A physical exam, blood draw, and radiographs were performed on the patient while at the hospital. WGS was performed on the DNA of the affected patient derived from EDTA blood, and genetic analysis focused on SNVs, small indels, and structural variants was performed to detect potential disease-causing mutations within the genome. PCR amplification and Sanger sequencing of a suspected region was performed to confirm presence of deletion.

Results: The patient presented for a cardiology consultation and displayed clinical signs of cardiac enlargement, pneumothorax, and joint hypermobility. Following genetic analysis, a roughly four kilobase deletion encompassing exon 24 of the FBN1 gene was detected, likely causing an in-frame deletion in the coding sequence.

Conclusions: Given the estimated impact of the mutation and the patient’s associated clinical signs, we suspect Marfan syndrome