glycogen storage disease

glycogen

 [gli´ko-jen]

a polysaccharide that is the chief carbohydrate storage material in animals, being converted to glucose by depolymerization; it is formed by and largely stored in the liver, and to a lesser extent in muscles, and is liberated as needed.

glycogen disease glycogen storage disease.

glycogen storage disease any of a group of genetically determined disorders of glycogen metabolism, marked by abnormal storage of glycogen in the body tissues. Type I is called gierke's disease; type II is called pompe's disease; type III is called forbes' disease; type IV is called amylopectinosis; type V is called mcardle disease; and type VI is called hers' disease. In type VII, a deficiency in phosphofructokinase affects muscle and erythrocytes, with temporary weakness and cramping of skeletal muscle after exercise. In type VIII, the enzyme deficiency is unknown, but the liver and brain are affected, with hepatomegaly, truncal ataxia, and nystagmus; the neurologic deterioration progresses to hypertonia, spasticity, and death. In type IX, a deficiency in liver phosphorylase kinase results in marked hepatomegaly, which may disappear in early adulthood. In type X, a lack of activity of cyclic AMP–dependent kinase affects the liver and muscle, with mild clinical symptoms. Called also glycogen disease and glycogenosis.

glycogen storage disease

n.

Any of various genetic diseases caused by deficiency of one of the enzymes involved in breaking down or synthesizing glycogen, resulting in storage of abnormal amounts or types of glycogen and often affecting the liver, muscles, or both. Also called glycogenosis.

A clinically benign autosomal recessive [MIM 232700] metabolic disorder caused by a deficit of glycogen phosphorylase [EC 2.4.1.1] encoded on 14q21-q22

glycogen storage disease

Glycogenosis Any of a group of 12 inherited AR defects in the ability to store and/or retrieve glucose from intracellular depots, resulting in accumulation of glycogen in liver, muscle, heart, kidney, and other tissues enzyme defects, and hepatosplenomegaly, cardiomegaly, mental retardation–eg, dancing eyes syndrome–GSD VIII

Glycogen storage disease

Type  Deficient enzyme

0 Hepatic glycogen synthetase

I Glucose-6-phosphatase

II Lysosomal acid maltase alpha-1,4 glucosidase

III Amylo-1,6 glucosidase ('debrancher' disease)

IV Amylo-1,4-1,6-trans-glucosidase–'brancher' disease

V  Myophosphorylase

VI Hepatic phosphorylase

VII Phosphofructokinase

VIII Inactive hepatic phosphorylase