Glycogen Storage Disease - Glycogen Storage Disease

Glycogen storage disease (GSD, also glycogenosis and dextrinosis) is the result of defects in the processing of glycogen synthesis or breakdown within muscles, liver, and other cell types.

GSD has two classes of cause: genetic and acquired. Genetic GSD is caused by any inborn error of metabolism (genetically defective enzymes) involved in these processes. In livestock, acquired GSD is caused by intoxication with the alkaloid castanospermine.

Prevalence

Overall, according to a study in British Columbia, approximately 2.3 children per 100 000 births (1 in 43,000) have some form of glycogen storage disease. In the United States, they are estimated to occur in 1 per 20,000-25,000 births. A Dutch study estimated it to be 1 in 40,000.

Types

There are eleven (11) distinct diseases that are commonly considered to be glycogen storage diseases (some previously thought to be distinct have been reclassified). (Although glycogen synthase deficiency does not result in storage of extra glycogen in the liver, it is often classified with the GSDs as type 0 because it is another defect of glycogen storage and can cause similar problems.)..

GSD type VIII: In the past, considered a distinct condition. Now classified with VI. Has been described as X-linked recessive.
GSD type X: In the past, considered a distinct condition. Now classified with VI.