Tag archives: genetic testing

In the world of human genetics, stories related to hereditary cancer predisposition syndromes have recently made quite a splash in the media.  For example, actress Angelina Jolie made a very public decision to have a double mastectomy in order to reduce her breast cancer risk.  There are other popular stories as well.  Although hereditary cancer predisposition syndromes are not as common in the canine population as they are in the human population, knowing a little information about these genetic conditions and how they work may impact breeding practices. 

What exactly is a hereditary cancer predisposition syndrome?  Those are a lot of complicated words.  Let’s dissect that phrase: 

                  Hereditary – inherited, genetic, passed from parent to offspring. 

                  Cancer – uncontrolled invasive abnormal cell growth. 

                  Predisposition – tendency towards or gravitation to. 

                  Syndrome – a group of symptoms with a single cause.

A hereditary cancer predisposition syndrome gives the affected individual a tendency to develop cancer.  Cancer, for the most part, is multifactorial.  That means there are genetic and environmental influences.  However, hereditary cancer predisposition syndromes have a much greater genetic influence than environmental influence ...

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 ...

At Paw Print Genetics we are passionate about prevention of inherited diseases of dogs. Through modern technologies, there are over 150 inherited diseases that can now be prevented through genetic testing of breeding dams and sires. Through use of the information gained from testing, informed decisions can be made for choosing breeding pairs to avoid producing pups afflicted with certain inherited diseases. Unfortunately however, not everyone that currently breeds dogs is aware of genetic testing availability or the importance of these genetic technologies in the overall well-being of their favorite breed. As a result, thousands of dogs are born every year with diseases that can now be prevented.

While the ability to prevent inherited diseases brings happy thoughts, the outcomes of dogs bred without the use of genetic technologies can be much less joyous. Historically, many dogs born with inherited disease were either euthanized or died due to complications of their condition. However, Paw Print Genetics was recently invited to visit a sanctuary for dogs called Double J Dog Ranch, where dogs with special needs find compassion, training, and eventually their forever home, through adoptions to families prepared for the unique opportunity of owning a special needs dog. Many of ...

My last blog talked about the basics of two types of inheritance for genetic conditions found in dogs: dominant and recessive.  To review, dominant conditions need one copy of the mutated gene in order for the dog to show symptoms.  Recessive conditions need both copies of the mutated gene inherited from each parent to have the disease.  Knowing the difference can change the way breeders choose which dogs to breed.  However, the wonderful world of genetics is not that simple.  Another pattern of inheritance is called X-linked, or sex-linked.  Although it is not as common as dominant and recessive; it is important to know which diseases follow this inheritance pattern, because it may impact breeding.

Dogs have 39 pairs of chromosomes (humans have 23).  Something dogs and humans have in common is the X and Y chromosomes determine gender.  XX is a female while XY is a male.  Females always give away an X chromosome to their offspring.  So, it is the male that determines gender for the next generation.  If he passes on the X chromosome, the offspring is female.  If he passes on the Y chromosome ...

Interactions with our clients are valuable to Paw Print Genetics. It helps us understand their concerns when it comes to genetic testing. One question that we have been asked on occasion is about the number of genetic tests we have available for a particular breed as compared to a different breed and what that number means for the health of that breed as a whole. For example, Paw Print Genetics currently offers 12 genetic tests for the Labrador retriever, which is more than any other breed. For some of our clients, the natural follow-up question after this discovery has been, “Are Labradors more unhealthy than other breeds?” Though there are many diseases that have been identified in the Labrador retriever, we cannot make the assumption that they are more unhealthy or carry more genetic problems as a whole than other breeds without doing some statistical evaluation of the entire dog population. However, to my knowledge, this potentially expensive and time-intensive evaluation has not been performed. Despite the fact that veterinarians may sometimes get the impression that certain breeds are overrepresented in regards to disease, there are many factors that must be considered when objectively evaluating the number of genetic ...

On April 30th, you will be able to order genetic testing for your dogs from Paw Print Genetics^TM. Before we could open our doors for clinical testing, we had a lot of work to do, work that involved my entire family and our extraordinary staff.  We had to build an entire laboratory from the ground up. Part of that process was validating our tests, which, as I’ll explain, is an important and necessary step – and one that involved many of you. 

After more than 20 years of working in human genetic diagnostic testing, I decided to use these skills to improve genetic testing for inherited canine diseases. We are so grateful for the support of the community of dog owners and breeders who participated in our validation studies from December 2012 through March 2013. As unknowns in this industry, we appreciate your trust that we were doing the right thing with your dog’s DNA.

We set up our laboratory, designed our tests and conducted our validation as if Paw Print Genetics were a human diagnostic laboratory. This means that we have all of the validation documentation that would be required if we were regulated by ...

As a continuation of my last blog related to reasons that breeders give for not needing to do genetic testing, I felt that one of these deserved an entire blog of its own. Some breeders will say, "no problem has ever occurred in this family of dogs and I have been breeding this line for 20, 30, 40 years. I don't need to do genetic testing." From my perspective, these breeders either have not been looking very hard, aren't being particularly forthcoming, or denial is a wonderful thing (and a river in Egypt). When I started getting involved in what was referred to as a "very healthy breed" (per the people who had been breeding them for 20, 30, 40 years), I recognized 3 problems in my first 2 dogs that I would consider "genetic". I had not been told to look out for or ask about any of these issues in my extensive research on the health of the breed. In fact as I was at the breeder's home being told of this issue in my new puppy's mother and grandmother I was thinking, "Gee, that is a genetic problem that no one ever told ...