Legend:
The glycogen synthetic and degradation pathways involve a set of enzymes whose failure can lead to a group of diseases collectively known as glycogen storage diseases. The enzymes are found in the cytoplasm, the endoplasmic reticulum and the lysosome and many are specific to individual organs. In the diagram, the enzymes whose failure leads to the distinct glycogen storage disorders are underlined and clicking on them will show a list of samples in the NIGMS Repository. GSD Ia and Ib are the result of the glucose-6-P phosphatase and transporter, the failure to breakdown glycogen in the lysosome is the basis of GSD II, GSD III is due to a deficiency of the debranching enzyme, GSD IV is caused by a deficiency of the branching enzyme in the glycogen synthetic pathway, GSD V and GSD VI are due to deficiencies of glycogen phosphorylase in the glycogen breakdown pathway, GSD VII is due to a deficiency of phosphofructokinase and GSD VIII/GSD IX can is the consequence of defects in any of the four isozyme/subunits of the enzyme.
By clicking on the symbol for the clinical disorder or enzymatic step in the diagram or the table, the list of the samples and the mutations in these samples appears. By clicking on the Gene Symbol a list of samples with characterized mutations appears.
References:
Amato, A.A. Sweet success--a treatment for McArdle's disease. N. Eng. J. Med. 26, 2481-2482.
Abstract
Chen, Y., Burchell, A. (1995). "Glycogen Storage Diseases." In The Metabolic and Molecular Bases of Inherited Disease(pp. 935-965), edited by Charles Scriver, Arthur Beaudet, William Sly and David Valle. New York: McGraw-Hill, Inc.
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