The Glycogen-Storage Diseases

Abstract

The glycogen-storage diseases (GSDs) are caused by enzyme defects of glycogen degradation. Some enzyme defects are mainly localized in the liver. Hepatomegaly and hypoglycemia are the main abnormalities. Some enzyme defects are localized in the muscles. Muscle cramps during exertion, progressive weakness and other features of myopathy are predominant. Other enzyme defects are generalized, and they present with variable symptoms related to the organs that are most seriously involved. GSDs are denoted either by the deficient enzyme or by a type number that reflects the historical sequence of elucidation. The latter presentation is used in this chapter. The main characteristics of each GSD type are summarized in Table 6.1.