Introducing MyDogDNA Pass and its reports - Part I: What is the Genetic Health Index (GHI) given by the MyDogDNA Pass?

MyDogDNA Pass is the dogs’ very first genetic health assessment that simultaneously delivers information about the breed disease heritage and genome-wide measured genetic diversity. This comprehensive of an analysis has not been available for dog owners ever before. Given the abundance of the genetic information delivered by one and single analysis, it was necessary to come up with a way that would help the dog owner to get an overview of the dog’s genetic health at one glance: the Genetic Health Index (GHI).

The Genetic Health Index (GHI) given by the MyDogDNA Pass is a value that describes the relative genetic health of a dog in relation to the other tested dogs in the MyDogDNA database. It is calculated based on the dog’s results in terms of tested disease heritage and measured genetic diversity (i.e. genome-wide measured heterozygosity). A dog with an average genetic health level has a GHI value of 100 and the rest of the tested dogs are normally distributed around it. Severe inherited diseases as well as low genetic diversity lower the index value. In practice, the GHI could decrease as low as close to zero, but in that case the dog would not only be homozygous but also affected of several disorders. In principle, the healthier the dog, the higher its index.

When observing the results of the dog, the owner should bear in mind that the purpose of the Genetic Health Index is to give an overview in relation to all of the other tested dogs within the database and only in terms of the measured genetic diversity and the disorders that are included in the MyDogDNA Pass. The index does not take into account the dog’s pedigree, test results from its parents or offspring or any other information which is not based on the MyDogDNA genome-wide analysis.

Picture 1. MyDogDNA Labrador
- An example of the Genetic Health Index
Picture 2. MyDogDNA Labrador
- An example of the measured diversity
of an individual (blue dot) and within breed (blue line)

Why can the Genetic Health Index change?

Because the Genetic Health Index is indeed describing the dog’s genetic health in relation to the other tested dogs within the database, it is not stable and is likely to change whenever new dogs are tested and your dog’s genetic health is calculated against theirs. The index is not breed-specific for two reasons. First, a breed-specific index value would make sense only after the population of tested dogs within breed is a few hundred of dogs and value changes due to new tested dogs would not be significant. Second, the Genetic Health Index should not be considered as a breeding value of the dog which could possibly happen if it was breed-specific. Within the current MyDogDNA dog population, the Genetic Health Index varies between 50 – 115. The dogs with the index above 100 are clear of all of the tested disorders and more diverse genetically.

Why the Genetic Health Index cannot be used to evaluate breeding decisions?

As already mentioned above, the Genetic Health Index is not breed-specific and should not be understood as a value that could help rank of match planned mating pairs. Mating of two dogs with high GHI would not necessarily lead to any healthier offspring as the two dogs could be closely related and potentially carrying same diseases.

To help breeders and Breed Clubs to best deploy the genetic information about their dogs, MyDogDNA Pass provides access to a whole new tool, MyDogDNA Breeder. It is a dog matchmaking tool which ranks the mating pairs based on the estimated genetic health of the offspring and shows whether the mating would produce genetically healthier puppies than the dogs within the current tested population. Indeed, MyDogDNA Breeder aims at maximizing the diversity within breed by placing first the most different dogs genetically and as last the ones that would carry same inherited disorders. Lethal combinations would not show up in the list at all.