Understanding your Mast Cell Tumor ("MCT") results

What is Mast Cell Tumor?

Mast Cell Tumor (MCT) is the most common malignant skin tumor in dogs. These tumors consist of white blood cells and tend to form masses in or under the skin on the head, neck, limbs, and trunk, but can also affect some internal organs. The average age of onset is 7 years, although tumors may develop at any age. The majority of MCTs can be cured by surgery alone.

Your dog’s genetic health results may show either of the following for the Mast Cell Tumor (“MCT”) estimated risk assessment. 

1. Increased Risk 
2. No Result

Increased Risk – If your dog’s MCT results show an increased risk, we know this can be scary. Please note that this is not a diagnosis but an estimated risk assessment based on your dog's genetic composition and breed ancestry. 

We’ve determined that certain breeds have an increased risk of developing certain health conditions (in this case, MCT). Additionally, we’ve identified numerous genetic variants associated with the disease in previously affected dogs. We combine ancestry percentage and genetic variant data with additional information that may influence the probability of disease, like sex,to develop an algorithm that estimates an individualized risk score for your dog. This is called ancestry-based risk. 

Breeders: We do not recommend using ancestry-based risk assessments like this as the sole factor in your decision-making as a breeder. MCT is not a monogenic condition (where a single genetic mutation can impact expression) so it won’t follow the inheritance patterns you may be familiar with. While this testing model looks at multiple genetic markers, it represents only a small fraction of risk within a breed and there are other genetic and non-genetic risk factors that our current algorithm cannot capture but that should be considered. 

To learn more about this condition and your dog’s personalized results, go to the Health tab of their profile within your MyEmbark account. If you have questions or concerns about your dog’s Embark results, please contact us. If you have concerns about your dog’s health, regarding MCT or any other medical condition, we strongly recommend you contact your veterinarian. 

No Result – If we were not able to provide a risk estimate for your dog at this time, it could be due to one or more of a few possible factors. 

• Breed ancestry requirement not met - Embark’s Mast Cell Tumor test is an ancestry-based risk assessment. Meaning, at this time, we are only able to provide a risk estimate for dogs with certain breed results and elevated percentages of those breeds. Currently, the most common breeds are American Pit Bull Terrier, Boston Terrier, and Boxer. If your dog’s ancestry does not have a significant portion of these breeds or closely related breeds, you likely would not have an MCT risk estimate at this time. 
• Dog not estimated to be at increased risk –  A combination of a dog’s breed ancestry (they have a low percentage of applicable breeds in their ancestry), sex (male dogs are less like to develop MCT), and evaluation of genetic markers determined that the dog is not at increased risk for MCT. 
• Genetic markers not clear – We could not successfully analyze the genetic markers known to be associated with MCT in your dog’s DNA.
• Genetic sex – Genetic sex is a contributing factor in determining the estimated risk for MCT. If your dog cannot be identified genetically as male or female, we cannot factor that into our estimated risk algorithm and therefore cannot provide an MCT result at this time. To learn more about genetic sex and intersexed dogs, please contact us.