Glycogen storage diseases: New perspectives

摘要

Glycogen storage diseases (GSD) are inherited metabolic disorders of glycogen metabolism. Different hormones, including insulin, glucagon, and cortisol regulate the relationship of glycolysis, gluconeogenesis and glycogen synthesis. The overall GSD incidence is estimated 1 case per 20 000-43 000 live births. There are over 12 types and they are classified based on the enzyme deficiency and the affected tissue. Disorders of glycogen degradation may affect primarily the liver, the muscle, or both. TypeⅠa involves the liver, kidney and intestine (andⅠb also leukocytes), and the clinical manifestations are hepatomegaly, failure to thrive, hypoglycemia, hyperlactatemia, hyperuricemia and hyperlipidemia. Type Ⅲa involves both the liver and muscle, and Ⅲb solely the liver. The liver symptoms generally improve with age. Type Ⅳ usually presents in the first year of life, with hepatomegaly and growth retardation. The disease in general is progressive to cirrhosis. Type Ⅵ and Ⅸ are a heterogeneous group of diseases caused by a deficiency of the liver phosphorylase and phosphorylase kinase system. There is no hyperuricemia or hyperlactatemia. Type Ⅺ is characterized by hepatic glycogenosis and renal Fanconi syndrome. Type Ⅱ is a prototype of inborn lysosomal storage diseases and involves many organs but primarily the muscle. Types Ⅴ and Ⅶ involve only the muscle.