Glycogen storage disease
Classification and external resources
Glycogen
ICD-10	E74.0
ICD-9	271.0
MeSH	D006008

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.^[1] 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.^[2]

[edit] Types

There are eleven 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.^[3] Now classified with VI.^[4] Has been described as X-linked recessive.^[5]

• GSD type X: In the past, considered a distinct condition.^[6][7] Now classified with VI.^[4]

Number	Enzyme deficiency	Eponym	Hypoglycemia?	Hepatomegaly?	Hyperlipidemia?	Muscle symptoms	Development/prognosis	Other symptoms
GSD type I	glucose-6-phosphatase	von Gierke's disease	Yes	Yes	Yes	None	Growth failure	Lactic acidosis, hyperuricemia
GSD type II	acid maltase	Pompe's disease	No	Yes	No	Muscle weakness	*Death by age ~2 years (infantile variant)	heart failure
GSD type III	glycogen debrancher	Cori's disease or Forbe's disease	Yes	Yes	Yes	Myopathy
GSD type IV	glycogen branching enzyme	Andersen disease	No	hepatosplenomegaly, cirrhosis	No	None	Failure to thrive, death at age ~5 years
GSD type V	muscle glycogen phosphorylase	McArdle disease	No	No	No	Exercise-induced cramps, Rhabdomyolysis		Renal failure by myoglobinuria
GSD type VI	liver glycogen phosphorylase	Hers' disease	Yes	Yes	No	None
GSD type VII	muscle phosphofructokinase	Tarui's disease	No	No	No	Exercise-induced muscle cramps and weakness (sometimes rhabdomyolysis)	growth retardation	Haemolytic anaemia
GSD type IX	phosphorylase kinase, PHKA2	-	No	No	Yes	None	Delayed motor development, Growth retardation
GSD type XI	glucose transporter, GLUT2	Fanconi-Bickel syndrome	Yes	Yes	No	None
GSD type XII	Aldolase A	Red cell aldolase deficiency	?	?	?	Exercise intolerance, cramps
GSD type XIII	β-enolase	-	?	?	?	Exercise intolerance, cramps
GSD type 0	glycogen synthase	-	Yes	No	No	Occasional muscle cramping

[edit] References

v • d • e Inborn error of carbohydrate metabolism: monosaccharide metabolism disorders (including glycogen storage diseases) (E73-74, 271) Sucrose, transport (extracellular) Disaccharide catabolism Lactose intolerance · Sucrose intolerance Monosaccharide transport Glucose-galactose malabsorption · Inborn errors of renal tubular transport (Renal glycosuria) · Fructose malabsorption Hexose → glucose Monosaccharide catabolism fructose: Essential fructosuria · Fructose intolerance galactose/galactosemia : GALK deficiency · GALT deficiency/GALE deficiency Glucose ⇄ glycogen Glycogenesis GSD type 0, glycogen synthase · GSD type IV, Andersen's, branching Glycogenolysis extralysosomal: GSD type V, McArdle, muscle glycogen phosphorylase/GSD type VI, Hers', liver glycogen phosphorylase · GSD type III, Cori's, debranching lysosomal/LSD: GSD type II, Pompe's, glucosidase Glucose ⇄ CAC Glycolysis MODY 2 · GSD type VII, Tarui's, phosphofructokinase · Triosephosphate isomerase deficiency · Pyruvate kinase deficiency Pyruvate catabolism PDHA · Fumarase deficiency Gluconeogenesis PCD · Fructose bisphosphatase deficiency · GSD type I, von Gierke, glucose 6-phosphatase Pentose phosphate pathway Glucose-6-phosphate dehydrogenase deficiency · Pentosuria Other Hyperoxaluria (Primary hyperoxaluria) see also fructose and galactose metabolism enzymes, intermediates; see also glycolysis enzymes, intermediates see also glycogenesis and glycogenolysis enzymes, intermediates; see also pentose phosphate pathway enzymes, intermediates