Glycogen Storage Disease Type Ia (Discovered in the German Pinscher)

Glycogen Storage Disease Type Ia (GSD Ia) is a severe metabolic disorder causing critically low blood sugar levels and liver enlargement. The associated genetic variant has been identified in the German Pinscher.

Found in

1 in 100,000 dogs

in our testing

Key Signs

Hepatomegaly, Hypoglycemia, Seizures, Failure to thrive, Death

Age of Onset

At birth

Present at birth


Autosomal Recessive

For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.

Likelihood of the Condition

High likelihood

At risk dogs are highly likely to show signs of this disease in their lifetime.

What to Do

Here’s how to care for a dog with GSD Ia

Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.

For Veterinarians

Here’s what a vet needs to know about GSD Ia

Glycogen storage diseases are a group of inherited disorders affecting carbohydrate metabolism. GSD Ia is characterized by severe hypoglycemia (low blood sugar) and hepatomegaly (an enlarged liver). Failure of glucose metabolism causes glycogen accumulation leading to progressive clinical signs, including weakness and seizures. Affected puppies may initially present when they are a few weeks old due to an enlarged abdomen and poor weight gain since birth. Without intervention, prognosis is poor as affected puppies rarely survive more than a few weeks. And, with palliative dietary therapy, long-term prognosis remains guarded.

Management of affected puppies consists of a high-starch diet fed frequently throughout the day to control hypoglycemia, with only small amounts of protein and fat in the diet to provide required nutrients. Palliative dietary therapy has been shown to improve immediate prognosis for affected puppies, with some surviving to adulthood. However, long-term complications remain prevalent. There are reports in which experimental gene therapy has shown success in improving the prognosis of this disorder in dogs.

For Breeders

Planning to breed a dog with this genetic variant?

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disorder is autosomal recessive, meaning two copies of the variant are needed for a dog to be at an elevated risk for being diagnosed with the condition. A carrier dog with one copy of the Glycogen Storage Disease Type Ia (Discovered in the German Pinscher) variant can be safely bred with a clear dog with no copies of the GSD Ia (Discovered in the German Pinscher) variant. About half of the puppies will have one copy (carriers) and half will have no copies of the variant. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disorder signs similar to the ones associated with this GSD Ia variant could develop due to a different genetic or clinical cause.

Technical Details

Gene G6PC
Variant Insertion
Chromosome 9
Coordinate Start 20,134,857
Coordinate End 20,134,858

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Christen, M., Reineking, W., Beineke, A., Jagannathan, V., Baumgärtner, W., Leeb, T. (2021). Polyadenine insertion disrupting the G6PC1 gene in German Pinschers with glycogen storage disease type Ia (GSD1A). Anim Genet, 52(6), 900-902. View the article