TESTING EXPLAINED DNA sequences that are close together on a chromosome tend to be inherited together. Because of this, we can use genetic variation surrounding a specific variant to infer the presence or absence of a variant that is linked to a health trait. *linkage tests are not as predictive of your dogs true genotype as a direct assays used in conditions we test for* It is further not a diagnosis and is only 1 possible factor that is thought to be linked to increase risk.