[Glycogenoses--genetic disorders leading to disturbed glycogen metabolism]

Glycogen storage diseases (GSD, glycogenoses) is a group of genetic disorders resulting from abnormal metabolism of glycogen--a polymeric molecule involved in intercellular glucose storage. Currently 13 different types of glycogenoses are known. They all result from mutations in genes for different enzymes, which directly or indirectly regulate glycogen synthesis and degradation. The clinical manifestation of GSDs encompasses primarily liver, striated muscle and brain tissue dysfunction. In those tissues glycogen plays a particularly important role. spectrum and severity of symptoms is very diverse, depending on both the type and subtype of the disease as well as on the individual features of the patient. The therapy is based mainly on application of an appropriate diet. Enzyme replacement therapy is currently available for GSD type II. For some of the other types the possibility for gene therapy is intensively investigated.