Dogs aren’t only humankind’s best friend; they’re also a valuable model species for medical genetics research.
Led by Adam Boyko, PhD, Chief Science Officer at Embark, a team of researchers from Cornell University College of Veterinary Medicine, University of Pennsylvania, China Agricultural University, and La Sierra University conducted a genetic study of over 4,200 dogs. They identified seven significant locations in the dog genome associated with six diseases.
This study was published in 2016 in the prestigious scientific journal Nature Communications. At the time of publication, it was the largest canine genome-wide association study to date.
Complex diseases are common
Many of the diseases we commonly think of are considered complex diseases. According to the National Human Genome Research Institute, a complex disease is caused by the interaction of both DNA (usually multiple genetic variants) and environmental factors. They are also called multifactorial diseases, indicating the many different factors that can contribute to disease.
Because they are influenced by many factors, the root causes of complex diseases can be difficult to pinpoint. There isn’t only one genetic cause of a complex disease.
Common examples of complex diseases include heart disease, diabetes, and cancer.
Genetic findings and complex diseases in dogs
Through this study, Dr. Boyko and the research team found many different locations in the genome associated with several types of complex diseases in dogs. Each location is called a “locus.”
As defined by the National Human Genome Research Institute, a locus is “a physical site or location within a genome (such as a gene or another DNA segment of interest), somewhat like a street address. The plural of locus is loci.”
The team found several genetic locations, or loci, associated with:
- Hip dysplasia
- Elbow dysplasia
- Idiopathic epilepsy
- Mast cell tumor
- Granulomatous colitis
The genetic finding associated with granulomatous colitis is particularly exciting, because the same region of DNA has been associated with inflammatory bowel disease (IBD) in humans. This condition is just one example of the many genetic similarities between dogs and humans.
The researchers also found genetic variants associated with body size, coat length, and shedding.
Dogs help us understand human disease
Dogs are an excellent animal model for human diseases. We have more than 350 diseases in common. These diseases often follow similar pathways in both dogs and humans, so understanding disease risk and progression in one can tell us about both.
In addition to demonstrating how dogs are a useful model for human medicine, these results act as a map for future scientific studies of complex disease in dogs.
Learn more about how dog DNA is helping us understand health and disease in humans.