Glycogen storage disease

Glycogen storage disease
Glycogen
Classification and external resources
Specialty
ICD-10	E74.0
ICD-9-CM	271.0
Patient UK	Glycogen storage disease
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.

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

Micrograph of glycogen storage disease with histologic features consistent with Cori disease. Liver biopsy. H&E stain.

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.

Number	Enzyme deficiency	Eponym	Incidence	Hypo- glycemia?	Hepato- megaly?	Hyperlip- idemia?	Muscle symptoms	Development/ prognosis	Other symptoms
GSD type I	glucose-6-phosphatase	von Gierke's disease	1 in 50,000- 100,000 births	Yes	Yes	Yes	None	Growth failure	Lactic acidosis, hyperuricemia
GSD type II	acid alpha-glucosidase	Pompe's disease	1 in 40,000 births-50,000	No	Yes	No	Muscle weakness	*Death by age ~2 years (infantile variant)	heart failure
GSD type III	glycogen debranching enzyme	Cori's disease or Forbes' disease	1 in 100,000 births	Yes	Yes	Yes	Myopathy
GSD type IV	glycogen branching enzyme	Andersen disease	1 to 500,000	No	Yes, also cirrhosis	No	None	Failure to thrive, death at age ~5 years
GSD type V	muscle glycogen phosphorylase	McArdle disease	1 in 100,000-500,000	No	No	No	Exercise-induced cramps, Rhabdomyolysis		Renal failure by myoglobinuria, second wind phenomenon
GSD type VI	liver glycogen phosphorylase	Hers' disease	1 in 65,000- 85,000 births	Yes	Yes	Yes	None
GSD type VII	muscle phosphofructokinase	Tarui's disease	1 in 1,000,000	No	No	No	Exercise-induced muscle cramps and weakness	growth retardation	Haemolytic anaemia
GSD type IX	phosphorylase kinase, PHKA2			Yes	Yes	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	Increasing intensity of myalgias over decades	Serum CK: Episodic elevations; Reduced with rest
GSD type 0	glycogen synthase	-		Yes	No	No	Occasional muscle cramping	Growth failure in some cases

External links

• Asociación Española de Enfermos de Glucogenosis