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$Unique_ID{BRK03820}
$Pretitle{}
$Title{Hers Disease}
$Subject{Hers Disease Glycogen Storage Disease VI Glycogenosis Type VI
Hepatophosphorylase Deficiency Glycogenosis Liver Phosphorylase Deficiency
Phosphorylase Deficiency Glycogen Storage Disease of Liver Andersen Disease
Forbes Disease Glycogenosis Type VIII Von Gierke Disease }
$Volume{}
$Log{}
Copyright (C) 1987, 1990, 1991 National Organization for Rare Disorders,
Inc.
401:
Hers Disease
** IMPORTANT **
It is possible the main title of the article (Hers Disease) is not the
name you expected. Please check the SYNONYMS listing on the next page to
find alternate names, disorder subdivisions, and related disorders covered by
this article.
Synonyms
Glycogen Storage Disease VI
Glycogenosis Type VI
Hepatophosphorylase Deficiency Glycogenosis
Liver Phosphorylase Deficiency
Phosphorylase Deficiency Glycogen Storage Disease of Liver
Information of the following diseases can be found in the Related
Disorders section of this report:
Andersen Disease
Forbes Disease
Glycogenosis Type VIII
Von Gierke Disease
General Discussion
** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only. It should not be used for diagnostic or treatment
purposes. If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.
Hers Disease is a hereditary glycogen storage disease which usually has
milder symptoms than most other types of glycogen storage disorders. It is
caused by a deficiency of the enzyme known as liver phosphorylase. Hers
Disease is characterized by enlargement of the liver (hepatomegaly),
moderately low blood sugar (hypoglycemia), elevated levels of acetone and
other ketone bodies in the blood (ketosis), and moderate growth retardation.
Symptoms are not always evident during childhood. Children are usually able
to lead normal lives. In some cases symptoms may be severe.
Symptoms
Symptoms of Hers Disease may not be apparent during childhood. Mild to
moderately low blood sugar can cause symptoms of faintness, weakness, hunger,
and nervousness. Growth rate may be slowed, and enlargement of the liver may
occur because of an excess accumulation of glycogen. Glycogen is the stored
form of energy derived from carbohydrates. In many cases the body can adapt
to low blood sugar levels and it is able to produce energy by other means.
Therefore, symptoms may go unnoticed for long periods of time.
Causes
Hers Disease is a hereditary glycogen storage disorder inherited through
autosomal recessive genes. The disorder is caused by a lack of the enzyme
known as liver phosphorylase. Because of this enzyme deficiency, the stored
form of energy derived from carbohydrates (glycogen) may accumulate in the
liver and cause liver enlargement (hepatomegaly).
Human traits including the classic genetic diseases, are the product of
the interaction of two genes for that condition, one received from the father
and one from the mother. In recessive disorders, the condition does not
appear unless a person inherits the same defective gene from each parent. If
one receives one normal gene and one gene for the disease, the person will be
a carrier for the disease, but usually will show no symptoms. The risk of
transmitting the disease to the children of a couple, both of whom are
carriers for a recessive disorder, is twenty-five percent. Fifty percent of
their children will be carriers, but healthy as described above. Twenty-five
percent of their children will receive both normal genes, one from each
parent and will be genetically normal.
Affected Population
All Glycogen Storage Diseases together affect less than 1 in 40,000 persons
in the United States. Symptoms of Hers Disease are usually not noticed until
adulthood although the disorder may present in childhood.
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 becomes available in the blood.
The following diseases are similar to Hers Disease. Comparisons may be
useful for a differential diagnosis:
Von Gierke Disease is a hereditary glycogen storage disease 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 amounts
of glycogen to be deposited in the liver and muscles. The heart may be
involved in some cases.
Andersen Disease is a glycogen storage disease inherited through
recessive genes. Symptoms of this disorder are caused by a lack of the
brancher enzyme (alpha-1,4-glucan 6-glucosyltransferase). Andersen Disease
is characterized by liver scarring (cirrhosis) which can lead to liver
failure.
Glycogen Storage Disease VIII is a sex-linked genetic disorder caused by
a deficiency of the enzyme liver phosphorylase kinase. The disorder is
characterized by slightly low blood sugar (hypoglycemia). Excess amounts of
glycogen (the stored form of energy that comes from carbohydrates) are
deposited in the liver, causing enlargement of the liver (hepatomegaly).
For more information on the above disorders, choose "Gierke," "Andersen,"
Forbes," and "Glycogen Storage Disease VIII" as your search terms in the Rare
Disease Database.
Therapies: Standard
Diagnosis of Hers Disease is based on a test for activity of the liver
phosphorylase enzyme. A small fragment of liver tissue is removed (biopsy)
and assayed for the activity of the enzyme. In persons with Hers Disease
this enzyme activity will be deficient.
Symptoms of Hers Disease are generally mild and the disorder usually
requires no treatment other than avoidance of prolonged tasting and
monitoring by a physician.
Therapies: Investigational
Dr. Y.T. Chen at Duke University Medical Center, at the request of the
Glycogen Storage Disease Association, is collecting DNA from patients with
Glycogen Storage Disease Type I to form a DNA bank for GSDI. Interested
patients may contact the Glycogen Storage Diseases Association for further
information. The address and phone number of the organization are listed in
the Resources section of this report.
This disease entry is based upon medical information available through
February 1991. Since NORD's resources are limited, it is not possible to
keep every entry in the Rare Disease Database completely current and
accurate. Please check with the agencies listed in the Resources section for
the most current information about this disorder.
Resources
For more information on Hers Disease, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
Association for Glycogen Storage Diseases
Box 896
Durant, IA 52747
(319) 785-6038
Research Trust for Metabolic Diseases in Children
Golden Gates Lodge, Weston Rd.
Crewe CW1 1XN, England
Telephone: (0270) 250244
National Digestive Diseases Information Clearinghouse
Box NDDIC
Bethesda, MD 20892
(301) 468-6344
For information on genetics and genetic counseling referrals, please
contact:
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
(914) 428-7100
Alliance of Genetic Support Groups
35 Wisconsin Circle, Suite 440
Chevy Chase, MD 20815
(800) 336-GENE
(301) 652-5553
References
THE MERCK MANUAL 15th ed: R. Berkow, et al: eds; Merck, Sharp & Dohme
Research Laboratories, 1987. Pp. 2078.
CECIL TEXTBOOK OF MEDICINE, 18th ed.: James B. Wyngaarden, and Lloyd H.
Smith, Jr., Eds.: W. B. Saunders Co., 1988. Pp. 425.