Genetic testing may seem simple on the surface. Order a test. If it’s positive, the dog will have symptoms. If it’s negative, there is no risk for the disease. Open and shut. However, there are many molecular details that can make genetic testing extremely complicated. Today’s topic is reviewing these facts and how they impact the diagnosis of a genetic condition and the chance it may happen again. My goal isn’t to bestow upon you an honorary degree in genetics, but to help you understand how these diseases are diagnosed and how genetic testing for those diseases is designed and interpreted.
Although genetic testing is expanding at an extremely fast pace, it is not perfect. Genetic testing can allow you eliminate certain conditions but, unfortunately, nobody has a crystal ball and can therefore, not exclude all possible diseases in any dog. Genetic tests are designed after a mutation causing a disease has been described in the medical literature. It may be a mutation common in a particular breed or it may be very rare. In addition, it may not be the only mutation in that gene, or there may be other genes ...