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Glycogen Storage Disease VIII

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Copyright 1987, 1989, 1991, 2000

Synonyms of Glycogen Storage Disease VIII

Disorder Subdivisions

General Discussion

Glycogen storage disease VIII is one of a group of hereditary disorders caused by a lack of one or more enzymes involved in glycogen synthesis or breakdown and characterized by deposition of abnormal amounts or types of glycogen in tissues. Excessive amounts of glycogen (which acts to store energy for later use) are deposited in the liver, causing it to become enlarged (hepatomegaly).

Symptoms

Glycogen storage disease VIII is usually a mild disorder. Symptoms may include an enlarged liver, increased liver glycogen (the stored form of energy from carbohydrates), and mild hypoglycemia (low blood sugar). Although inflammation of the liver may sometimes occur, liver function is usually normal and the disorder may be undetected throughout life.

Causes

Glycogen storage disease VIII is an X-linked genetic disorder caused by a deficiency of the enzyme liver phosphorylase kinase. This deficiency causes deposits of excessive amounts of glycogen in the liver. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother.

X-linked recessive disorders are conditions that are coded on the X chromosome. Females have two X chromosomes, but males have one X chromosome and one Y chromosome. Therefore, in females, disease traits on the X chromosome can be masked by the normal gene on the other X chromosome. Since males only have one X chromosome, if they inherit a gene for a disease present on the X, it will be expressed. Men with X-linked disorders transmit the gene to all their daughters, who are carriers, but never to their sons. Women who are carriers of an X-linked disorder have a 50 percent risk of transmitting the carrier condition to their daughters, and a 50 percent risk of transmitting the disease to their sons.

Affected Populations

All glycogen storage diseases together affect fewer than 1 in 40,000 persons in the United States. Glycogen storage disease VIII affects more males than females and usually begins during infancy; about 10% of patients with this disorder are females whose symptoms are mild.

Related Disorders

Glycogen storage diseases are caused by inborn errors of metabolism in which the balance between stored energy (glycogen) and available energy (sugar or glucose) is disturbed. Too much glycogen tends to be stored in the liver and muscles and too little sugar is available in the blood.

Symptoms of the following diseases may be similar to glycogen storage disease VIII. Comparisons may be useful for a differential diagnosis:

Von Gierke disease (glycogenosis I) is a glycogen storage disease. This hereditary metabolic disorder is caused by an inborn lack of either the enzyme glucose-6-phosphatase or the enzyme glucose-6-phosphate translocase. These enzymes are needed to convert the main carbohydrate storage material (glycogen) into sugar (glucose) which the body uses for its energy needs. A deficiency of these enzymes causes deposits of excess glycogen in the liver and kidney cells.

Forbes disease (glycogenosis III; Cori disease) is another genetic glycogen storage disease. This disorder is caused by a lack of a debrancher enzyme (amylo-1,6-glucosidase). This enzyme deficiency causes excess glycogen (the main carbohydrate storage material) to be deposited in the liver and muscles. The heart may be involved in some cases.

Andersen disease (glycogenosis VI) is a glycogen storage disease inherited through recessive genes. Symptoms of this disorder are caused by a lack of a brancher enzyme (alpha-1,4-glucan 6-glucosyltransferase). The lack of this enzyme causes an abnormality in the structure of the main carbohydrate storage material (glycogen). Andersen disease is characterized by scarring of the liver (cirrhosis) sometimes leading to liver failure.

Hers disease is a genetic form of mild glycogen storage disease. The disorder is caused by a deficiency of the enzyme liver phosphorylase. Hers disease is characterized by enlargement of the liver (hepatomegaly), low blood sugar (hypoglycemia), elevated levels of acetone and other ketone bodies in the blood (ketosis), and growth retardation. Symptoms are not always evident during childhood, so children are usually able to lead normal lives. In other cases symptoms may be more severe.

For more information on the above disorders, choose "Gierke," "Forbes," "Andersen," and "Hers" as your search terms in the Rare Disease Database.

Standard Therapies

Treatment is usually not necessary for this disorder in its mild form.

Investigational Therapies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.

For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com

Genetic counseling will be helpful for families of children with glycogen storage disease VIII.

Organizations related to Glycogen Storage Disease VIII

References

TEXTBOOK
The Merck Manual. M. H. Beers and R. Berkow, Eds., 17th ed., Merck Research Laboratories, 1999, Pp. 2387-89.

Cecil Textbook of Medicine. J.C. Barnett and F. Plum, Eds. 20th ed., W. B. Saunders Company, 1996, Pp. 1082-83.

JOURNAL ARTICLE
[Glycogen Storage Disease Type VIII. T. Nishigaki. Ryoikbetsu Shokogun Shirizu. (1998, (18 Pt 1)). Pp. 56-9.

A Female Case of Type VIII Glycogenosis Who Developed Cirrhosis of the Liver and Hepatocellular Tumor. S. Shiomi et al., Gastroenterol Jpn. (Dec 1989, 24 (6)). Pp. 711-14.

Glycogen Storage Disease: Recommendations for Treatment. J. Fernandes et al., Eur J Pediatr. (Apr 1988, 147 (3)). Pp. 226-28.

Glycogenosis Type VIII. M. Kornfeld et al., J Neuropathol Exp Neurol. (Nov 1984, 43 (6)). Pp. 568-79.

Report last updated: 2008/05/24 00:00:00 GMT+0