The glycogen storage diseases (GSD) are a group of autosomal recessive disorders of glycogen metabolism that occur in all species and result in glycogen accumulation in tissue and disturbed glucose homeostasis. Clinical signs of disease vary, depending on severity of the enzyme defect, subcellular compartmentalization of the enzyme, and tissues in which the enzyme is normally expressed. The disease is characterized by a deficiency in glycogen debranching enzymes. Affected dogs show less symptoms in early life, but older animals suffer from lethargy and episodic hypoglycemia with collapse.
Inheritance: Autosomal reccesive.Read more
Mutation: AGL gene
Genetic test: Disease or carrier can be identified by genetic testing at any age. The real-time PCR method used for testing is extremely accurate and allows complete differentiation between affected animals, carriers and healthy dogs.
Regarding to the presence of mutations dogs are classified into three groups:
- Affected (mut/mut)- both alleles carry mutation, disease is clinically expressed
- Carrier (mut/wt)- one of two alleles carry mutation, disease is not clinically expressed
- Wild type (wt/wt)- mutation is not detected, normal genotype, healthy animal
For each group different breeding strategies can be applied in order to control the spread of the disease. Breeding with affected or carrier dogs should be avoided. In the case that the owner holds particularly valuable dog, which carry the mutation, such dog should be bred with healthy/unaffected individual. In the case where an affected dog was bred with healthy individual all animals of the offspring are carriers therefore genetic testing is not necessary. When first generation of dogs is bred again with healthy/unaffected animal 25% of the second generation of dogs is free of mutations. Second generation should be tested and only dogs which do not carry mutation are used for further breeding.
Affected breeds: Curly Coated Retriever
Sample: EDTA whole blood (1.0 ml) or buccal swabs. Detailed information about sampling can be found here.