Glycogen storage disease (GSD Ia)

Glycogen storage disease type 1 (GSD 1) is caused by a dysfunction of the glycose metabolism, which leads to mass storage of glycogen in organs. The ability to efficiently bind glucose to glycogen and break it down again depends on the highly branched structure of glycogen. The glycogen branching enzyme (GBE) is necessary for the formation of this branched structure, while the glycogen debranching enzyme (GDE) is necessary for its breakdown.

The function of glycogen branching enzyme (GBE) is altered by a variant, that leads to a change in the structure of glycogen and inhibits its degradation. Therefore, accumulation of glycogen in liver, muscle and nerve cells results in gradual dysfunction of these organs. Affected puppies experience glucose deficiency very early after birth and exhibit symptoms like depression, bad nutritional state and slow growth.