Tag archives: canine genetic testing

Beyond Dominant and Recessive: X-Linked Canine Inheritance

Beyond Dominant and Recessive:  X-Linked Canine Inheritance

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 ...

Have You Connected With Us On Facebook?

Have You Connected With Us On Facebook?

Social media has been a very successful avenue for Paw Print Genetics to reach our customers. We have connected with fans all over the United States, Canada, the United Kingdom and even Australia! Dog lovers all over the world understand the importance of optimal canine genetic health and are choosing Paw Print Genetics for their testing needs.

One of the most valuable reasons to connect with us via Facebook is for our special discounts and promotions. Each month has a theme for our Breed of the Week posts which discuss the breeds history, health, temperament, and includes a special discount on testing. We also post any show discounts or current promotions for you to use at checkout. Our Facebook fans and newsletter recipients are the first to know when new disease tests are released. 

On our website we have a wide selection of blogs and our Facebook fans are the first to read them.  Several authors write informative articles that explain genetic diseases, canine safety tips, breed of the week profiles, and developments within our lab and in the canine health world.

Facebook is a great way to connect with friends and others who share the same passion ...

Ask the Vet: “I’m confused about the different types of PRAs."

Ask the Vet: “I’m confused about the different types of PRAs."

As most canine breeders can tell you, some of the diseases most commonly tested for in pure bred dogs are the eye diseases falling under the general term, Progressive Retinal Atrophies (PRA).  However, because the various types of PRA can present very similarly, many people are unaware that PRA is not just one disease, but is a general category of disease known to be caused by a number of different genetic mutations in several different genes.  The prevalence of each type of PRA varies by breed and some forms have only been identified in a single breed.  In addition to confusion regarding the variety of disorders grouped under the PRA label, there is often confusion regarding the method used to name the individual types of PRA seen.  A good place to start in understanding the common names of these diseases would be to look at the general types of the disease and how they manifest.  In order to understand the various types however, we must first learn a little about how the eye works.

The retina is a light-sensitive layer of sensory tissue that lines the inner surface of the eye.  Light that shines ...

Canine neuronal ceroid lipofuscinosis or Batten disease

Canine neuronal ceroid lipofuscinosis or Batten disease

The neuronal ceroid lipofuscinoses are a group of inherited lysosomal storage disorders.  Lysosomes are structures in cells referred to as the stomach of the cell that breakdown waste products and other byproducts in the cell.  NCL affected dogs lack one of several enzymes necessary for the normal breakdown of certain types of fat or protein in the cells (called lipopigments.)  As this "debris" accumulates in neuronal cells (and to a lesser extent in other cells), the animal's mental and motor functions deteriorate.

Dogs with NCL start out as apparently normal and fully functional dogs.  Depending on which subtype of NCL they have, they will begin developing symptoms anywhere from 6 months to 4-6 years of age (for the adult onset varieties).  NCL is found in both humans and dogs as well as other species and share symptoms that include a progressive loss of mental and physical nervous system functions.    These exhibit as mental/intellectual decline and motor disturbance progressing to seizures, motor problems such as lack of muscle coordination, abnormal gait, difficulty balancing, visual disturbances progressing to blindness and behavioral changes including aggressiveness, dementia, aimless wandering behavior with episodes of confusion, depression and ...

Importance of Accuracy When Relying on Canine Genetic Testing

Importance of Accuracy When Relying on Canine Genetic Testing

Everyone at Paw Print GeneticsTM is excited about our grand opening and bringing our clinical genetic testing services to the canine community.  As discussed in the last blog by founder and CEO, Dr. Lisa Shaffer, a great deal of time and care has gone into ensuring the quality and accuracy of our testing.  I cannot stress enough how incredibly important this validation process is and the need for the laboratory to have checks and balances to truly make certain that your canine genetic test results are accurate.

Several years ago, a friend ordered genetic testing to determine if all of the puppies her black male produced would be black or if he would have the potential to produce the other colors found in the breed.  She had several individuals who were interested in using her male but a portion of these were only interested in using him if he could produce more colors in his puppies than only black.  After paying and waiting for the results, she received the news from the laboratory that did the testing that he would only sire black puppies and informed the interested parties of this result.  Several of ...

Canine Genetic Testing is Serious Business

Canine Genetic Testing is Serious Business

On April 30th, you will be able to order genetic testing for your dogs from Paw Print GeneticsTM. 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 ...

Valid Canine Genetic Testing or "Accuracy" of Canine Genetic Testing

Valid Canine Genetic Testing or "Accuracy" of Canine Genetic Testing

There is a trend in the dog world for people to create a list of health clearances on their dogs as long as their arm. There is certainly nothing wrong with a long list of health clearances if those health clearance are valid for the breed - and that is a big if.

I spoke in a previous blog about the fact that not all diseases that appear to be the same are the same. An extremely involved genetic disorder can appear to be identical in two affected individuals, yet can actually have extremely different causes. More specifically, it can be caused by different gene mutations or even two entirely different genes. In the previous blog we discussed the different types of PRA that have been found in different breeds.

With a slightly different focus I want to discuss specifically how this affects the "accuracy" of genetic testing. We all know genetic testing is "very accurate." But that assumes you are testing for the right thing and that the specific gene test is informative. One example is the melanophilin gene. Two different mutations related to this gene have been identified to be associated with dilute coat color (called blue or the ...

Understanding the Genetics of Disease in Your Dog

Understanding the Genetics of Disease in Your Dog

Many people have misconceptions about genetic terms and what these terms mean related to the inheritance of a health issue in a dog, a family of dogs or a breed. I wanted to take a moment to step back and discuss some of these commonly used terms to help people understand them more clearly.

Most genes (and the genes that will be tested for at Paw Print Genetics ) are located on the chromosomes contained in the nucleus found in most cells. Chromosomes come in 39 pairs (and thus, the genes come in pairs). One through 38 are the numbered pairs (called autosomes) the 39th pair are the sex chromosomes; females have two X chromosomes and males have an X and a Y chromosome. The X is larger and has more genes. Because males have only one copy of the X chromosome (and therefore only one copy of many genes found on the X chromosome), they are at risk of having certain diseases that are unlikely to affect females.
Autosomal conditions are found on one of the numbered chromosomes and X-linked conditions are found on the X chromosome. Each gene has a particular location on the chromosome called a locus. Different ...