Glycogen storage diseases - Phenotypic, genetic, and biochemical characteristics, and therapy

Glycogen storage diseases (GSD), or glycogenoses, are inherited disorders c aused by deficiencies of enzymes that regulate the synthesis or degradation of glycogen. This article reviews the clinical features, short- and long-t erm complications, diagnosis, and management of the hepatic glycogenoses th at typically cause hypoglycemia. Whether long-term complications can be pre vented by dietary therapy is unclear; but meticulous adherence to dietary t herapy prevents hypoglycemia, ameliorates the biochemical abnormalities, de creases the size of the liver, and results in normal or nearly normal physi cal growth and development. Serious long-term complications occur, however, especially in patients with types I and Ill GSD. GSDs caused by lack of ph osphorylase activity are milder disorders with a good prognosis.