What is COI (Coefficient of Inbreeding)?

COI is available in all kits except for our Breed ID kit. Breed ID customers can purchase a Health upgrade to include this information. 

What is COI?

Inbreeding is a measure of how closely related your dog’s parents were. The higher the inbreeding coefficient, the more closely related the parents. In general, higher inbreeding coefficients are associated with increased incidence of genetically inherited conditions, reduced fecundity, and reduced life span.

Below is a sample COI for an English Bulldog in our database.

How far back does the coefficient of inbreeding (COI) go?

Our report covers COI across the whole canine genome.

Unlike pedigree-based COI, which is an inference based on the presumed likelihood of inheriting part of a genome from a known ancestor, we provide a more accurate measure: genetic COI. We use tens of thousands of markers distributed across your dog’s genome to identify segments of chromosomes that are highly likely to have been inherited from a common ancestor. In contrast, tests that evaluate only small parts of the genome or estimate homozygosity based on “identity by state” can miss long inbreeding tracks (sometimes entire chromosomes). By using markers spaced throughout the genome, our test directly measures long (and short) inbreeding tracks, providing you with the most accurate COI estimate possible for your dog.

To learn more about COI, please see the following articles:

• Inbreeding Explained
• Oedipus Rex: Dog Inbreeding, Its Consequences, and Its Quantification
• What is DLA?