Glycogen storage disease due to liver or muscle glycogen phosphorylase kinase deficiency (Q100846)

Glycogen storage disease due to liver and muscle phosphorylase kinase (PhK) deficiency is a benign inborn error of glycogen metabolism. It is the mildest form of GSD due to PhK deficiency. Patients have marked hepatomegaly and mild muscular hypotonia. Hypoglycaemia may occur only after prolonged fasting. These symptoms improve with age and adults are generally asymptomatic.