Glycogen storage disease what are the two types

• Excess glycogen storage can lead to tissue damage: E.g. Von Gierke disease- liver glucose 6 phosphatase deficiency (hypoglycaemia, enlarged liver) • Insufficient glycogen degradation can lead to hypoglycaemia and poor exercise tolerance: E.g. McArdle disease- muscle glycogen phosphorylase deficiency (exercise-induced muscle pain and cramps)