Glycogen branching enzyme leads to increased osmotic pressure resulting in cellular swelling and death. The tissues most affected by this disease are the liver, heart, and neuromuscular system, areas with the greatest levels of glycogen accumulation. Abnormal glycogen buildup in the liver interferes with liver functioning and can result in an enlarged liver and liver disease. In muscles, the inability of cells to efficiently breakdown glycogen due to the severe reduction or absence of branching can lead to muscle weakness and atrophy. At least three mutations in the GBE1 gene have been found to cause another disease called adult polyglucosan body disease (APBD).
Glycogen storage disease type 0 of asymptomatic and oligosymptomatic siblings in several glycogen-storage disease type 0 families has suggested that glycogen-storage disease type 0 is underdiagnosed. The major morbidity is a risk of fasting hypoglycemia, which can vary in severity and frequency. Major long-term concerns include growth delay, osteopenia, and neurologic damage resulting in developmental delay, intellectual deficits, and personality changes. No sexual predilection is observed because the deficiency of glycogen synthetase activity is inherited as an autosomal recessive trait. Glycogen-storage disease type 0 is most commonly diagnosed during infancy and early childhood. Glycogen storage disease type 0 Glycogen storage disease type 0 is a