DNA Testing Facts
Hello, everybody!
Why is it important to learn the facts about DNA testing?
Well when you educate yourself on this topic, you will be able to accurately understand test results and decipher between what should and shouldn't be concerning about the companies analysis.
Understanding Results
Clear
If the dog's result is "clear", it means that the dog is not a carrier of a health condition nor is it at risk for developing any clinical diseases or conditions.
Carrier / Notable
If the dog's result is "Carrier or Notable ", it means that the dog carries one copy of a health condition. This result will not impact or affect the dog's health in any way. It means the dog carries this variant and will pass the carrying status on to ~50% of its offspring. If a dog has a carrier status the dog is perfectly healthy to keep breeding as long as the dog is never bred to another carrier of that same disease or condition.
Affected, Positive, Increased Risk
If the dog's result is "Affected, Positive or At Increased Risk", it usually means that the dog carries two copies of a health condition. This result will most times mean the dog is likely to be affected by a health problem. Since the dog has two copies of the condition it means that this dog has a high chance of passing it down to their puppies every time. This means this dog should not be bred. This result is not the case for "Linkage or Provisional" tests.
Should You Be Worried About Provisional Or Linkage Test Results Being At Increased Risk?
No, you shouldn't, and this is why.
What is a Linkage Test?
DNA sequences that are close together on a chromosome tend to be inherited together. Because of this, they can use genetic variation surrounding a specific variant (i.e. "linked" to it) to infer the presence or absence of a variant that is associated with a health condition or trait.
Butt.... Embark states that
Linkage tests are not as predictive of your dog's true genotype as direct assays, which they use on most "other genetic conditions" they test for....
What Are Provisional Results?
Embark states that they use a high-density, high-accuracy genotyping platform with single-probe reproducibility of 99.9% with >99% call rates. Their "standard" health tests have been validated using a known carrier and affected samples to ensure design accuracy and use multiple probes to ensure highly accurate results (essentially 100%).
Butt..... Embark states that
Provisional tests are for rare disorders for which
DNA from carrier and affected individuals are not available for calculating test reliability, or for structural variants where more testing is needed to ensure the same level of accuracy.
They also ask that if you are a researcher or breeder with access to
DNA from a carrier or affected individual and are interested in helping them validate tests, to please contact them at research@embarkvet.com.
It clearly states that it's not reliable or accurate.
Will a DNA Breed Identification Test Prove My Dog Is Purbred?
Absolutely Not!!
Contrary to what DNA companies say about the accuracy of their breed verification testing, this is without a doubt not as precise as they lead you on to be. As I stated previously, if you have a purebred dog, you don’t need a DNA test to learn its ancestry or prove if it's indeed a purebred. Currently, there is no DNA company that guarantees their breed testing is 100% accurate, it's more for fun to see what they "assume" the dog is.
Here are a few links to several websites that go into detail on this topic.
https://americanpomskykennelclub.org/knowledge-base/dna-discussion
