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$Unique_ID{BRK03832}
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$Title{Huntington's Disease}
$Subject{Huntington's Disease Chronic Progressive Chorea Degenerative Chorea
HD Hereditary Chorea Hereditary Chronic Progressive Chorea Huntington's Chorea
Very Early Onset Huntington's Disease (VEOHD) Woody Guthrie's Disease
Hallervorden-Spatz Disease Olivopontocerebellar Atrophy (OPCA) Syndenham's
Chorea Wilson's Disease Tourette Syndrome }
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Copyright (C) 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993
National Organization for Rare Disorders, Inc.

18:
Huntington's Disease

** IMPORTANT **
It is possible that the main title of the article (Huntington's Disease)
is not the name you expected.  Please check the SYNONYMS listing to find the
alternate name and disorder subdivisions covered by this article.

Synonyms

     Chronic Progressive Chorea
     Degenerative Chorea
     HD
     Hereditary Chorea
     Hereditary Chronic Progressive Chorea
     Huntington's Chorea
     Very Early Onset Huntington's Disease (VEOHD)
     Woody Guthrie's Disease

Information on the following diseases can be found in the Related
Disorders section of this report:

     Hallervorden-Spatz Disease
     Olivopontocerebellar Atrophy (OPCA)
     Syndenham's Chorea
     Wilson's Disease
     Tourette Syndrome

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.


Huntington's Disease is an inherited progressively degenerative disorder
of the nervous system.  This disorder is characterized by involuntary muscle
movements (chorea) and the loss of cognitive abilities (dementia).

Symptoms

Huntington's Disease is characterized by rapid uncontrollable muscle
movements such as tics or muscle jerks (choreiform movements or chorea).
This disorder causes a loss of coordination and personality changes.  As the
disease progresses, the ability to speak may be impaired, memory may fade and
the involuntary jerky muscle movements (chorea) become more severe.

Huntington's Disease runs a 10 to 25 year progressive course.  As the
disorder progresses, the chorea may subside and there may be an absence of
movement (akinesia).  Dementia gradually develops.  Patients with
Huntington's Disease are at high risk of developing pneumonia as a result of
being bedridden and undernourished.

There are powerful diagnostic tools available to aid in the diagnosis of
Huntington's Disease.  These include:  magnetic resonance imaging (MRI);  CT
scan or computerized tomography (an advanced X-ray technique showing detailed
cross sections of the brain); EEG or electroencephalograph (an instrument
that records electrical activity of the brain); and neuropsychological and/or
genetic tests.

Causes

Huntington's Disease is inherited as an autosomal dominant trait.  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.  In dominant disorders a single copy of the disease gene (received
from either the mother or father) will be expressed "dominating" the other
normal gene and resulting in the appearance of the disease.  The risk of
transmitting the disorder from affected parent to offspring is fifty percent
for each pregnancy regardless of the sex of the resulting child.

Scientific research suggests that when the Huntington's Disease gene is
inherited from the mother (maternal inheritance), the first symptoms of this
disease may be delayed past the age of fifty in many cases.  The evidence
also suggests that when the Huntington's Disease gene is inherited from the
father (paternal inheritance), symptoms seem to begin at an earlier age.

The gene that causes Huntington's Disease is located on chromosome 4.
Although scientists have not yet found the exact gene that causes
Huntington's Disease, they have identified a "chromosome marker" which makes
genetic testing possible.

Affected Population

Huntington's Disease affects approximately 1 in 10,000 people in the United
States.  An estimated 15,000 to 25,000 Americans have Huntington's Disease
and another 150,000 people may be are at risk for the disease.  This disease
occurs equally in males and females, and is most common in Caucasian
Americans.

A very rare childhood form of Huntington's Disease accounts for
approximately 10 percent of all cases.  This form of the disorder may occur
in children as young as 2 years of age.

Related Disorders

Symptoms of the following disorders can be similar to those of Huntington's
Disease.  Comparisons may be useful for a differential diagnosis:

Hallervorden-Spatz Disease is a rare progressive disorder that affects
muscle movement.  It is associated with the degeneration of the nervous
system.   Hallervorden-Spatz Disease is characterized by uncontrolled muscle
movements (dystonia), muscular rigidity, and the loss of cognitive abilities
(dementia).  The symptoms of this disease typically begin during childhood,
although occasionally the disease begins in adulthood.  Approximately one-
third of people with Hallervorden-Spatz Disease experience sudden jerky
muscle movements.  Other less frequent symptoms may include joint pain
(dysarthria), mental retardation, facial grimacing, impaired speech
(dysphasia), and impaired vision.  (For more information on this disorder,
choose "Hallervorden-Spatz" as your search term in the Rare Disease
Database).

Olivopontocerebellar Atrophy is a group of rare inherited disorders that
are characterized by the progressive loss of the cerebellar cortex and other
brain tissue.  Five different types of Olivopontocerebellar Atrophy have been
identified.  The symptoms vary widely depending on the type of
Olivopontocerebellar Atrophy present.  Generally this disorder is
characterized by an impaired ability to coordinate muscle movement, tremors,
involuntary jerky muscle movements, impaired speech (dysphasia), loss of
cognitive abilities and mental deterioration.  A wide variety in severity and
age of onset may be found in all types of Olivopontocerebellar Atrophy.  (For
more information on this disorder, choose "Olivopontocerebellar Atrophy" as
your search term in the Rare Disease Database).

Sydenham's Chorea is a disorder of the nervous system that begins
abruptly after a streptococcal infection such as strep throat or rheumatic
fever.  This disorder usually affects young children and adolescents.
Syndenham's Chorea is characterized by rapid, involuntary, non-repetitive
muscle movements that may gradually become more severe and frequent.  The
muscles of the arms and legs are usually most affected.  Speech may also be
impaired.  Other common symptoms may include clumsiness and facial grimacing.
Chorea-like muscle movements tend to disappear with sleep.  This disorder
usually subsides in 3 to 6 months with no permanent neurological or muscle
damage.  (For more information on this disorder, choose "Syndenham" as your
search term in the Rare Disease Database).

Wilson's Disease is a rare inherited disorder that affects the liver,
eyes and neuromuscular system.  Symptoms develop due to the excessive
accumulation of copper in body tissues, particularly the liver, brain and
eyes.  Early diagnosis and treatment of Wilson's Disease may prevent serious
long-term disabilities.  Neuromuscular symptoms of Wilson's Disease generally
appear between the ages of 12 and 32 years.  These symptoms may include
drooling, joint pain (dysarthria), impaired speech (dysphasia), lack of
muscle coordination, tremors, involuntary jerky muscle movements, muscle
rigidity and double vision.   Other late symptoms of Wilson's Disease may
include a decrease in cognitive abilities, behavioral changes, depression and
other psychiatric disturbances.  (For more information on this disorder,
choose "Wilson" as your search term in the Rare Disease Database).

Tourette Syndrome is a neurological movement disorder that usually first
appears between the ages of 2 to 16 years.  Initial symptoms are often rapid
eye blinking or facial grimaces, but many parts of the body can be affected.
Symptoms wax and wane, with new symptoms replacing old ones that have
disappeared.  Tourette Syndrome is not progressive nor degenerative, and
patients live a normal life span.  Muscle and vocal tics characterize this
disorder.  (For more information on this disorder, choose "Tourette" as your
search term in the Rare Disease Database.)

Therapies:  Standard

Treatment for Huntington's Disease is symptomatic and supportive.  There are
some treatments that may alleviate various symptoms temporarily.
Phenothiazines and other neuroleptic drugs are marginally effective for the
treatment of some behavioral symptoms.  Special high calorie food
preparations can help the patient to maintain weight and avoid choking during
the later stages of Huntington's Disease.

DNA linkage analysis is a method of genetic testing that is used to
determine whether a person is carrying a gene for a specific disorder.  This
test is now being widely used at genetic clinics for Huntington's Disease.
People who have relatives with Huntington's Disease may be tested with DNA
linkage analysis for the Huntington's Disease chromosome marker.  This test
is 99 percent accurate when enough family members are tested.

Therapies:  Investigational

Several drugs are under investigation for possible use in the treatment of
Huntington's Disease.  The orphan drug cannabidiol is currently in clinical
trials to test its effectiveness as a possible treatment for Huntington's
Disease.  Interested patients should have their physician contact:

     Paul F. Consroe, Ph.D.
     Department of Pharmacology & Toxicology
     College of Pharmacology
     University of Arizona
     Tucson, AZ  85721

Another experimental drug, MK-801, is being tested to determine whether
it can block the effects of quinolinic acid.  Quinolinic acid is thought to
damage brain cells (neurons) in people with Huntington's Disease.

The drug idebenone (AVAN) is being used in Japan to treat patients with
cognitive problems resulting from strokes.  This drug appears to prevent
brain cell degeneration.  In the United States idebenone is being tested on a
small number of people with Huntington's Disease to determine its possible
therapeutic value.  Interested patients should have their physicians contact:

     Huntington's Disease Center
     Johns Hopkins University
     School of Medicine
     Drug Study Project
     600 N. Wolfe St.
     Baltimore, MD  21287-7281
     [phone]

Drs. Allen Rubin at the School of Medicine and Dentistry of New Jersey
and Ira Shoulson at the University of Rochester, NY are testing the drug
Prozac for its possible value in the treatment of Huntington's Disease.  Both
studies are restricted to those people in early stages of Huntington's
Disease and involve restrictions on the prescribed medications that are taken
by the patients.  Eligible patients who would like to participate in this
study, may have their physician contact one of the following:

     Robert Wood Johnson Medical School
     Dr. Allen J. Rubin, Asst. Prof. of Neurology
     Camden,  NJ
     [phone]

     University of Rochester
     Charlyne Miller, RN, MS, Nurse Coordinator
     601 Elmwood Ave.
     P.O. Box 673
     Rochester, NY  14642
     [phone]

This disease entry is based upon medical information available through
March 1993.  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 Huntington's Disease, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     Huntington's Disease Society of America
     140 W. 22nd Street, 6th Floor
     New York, NY  10011
     [phone]

     NIH/National Institute of Neurological Disorders & Stroke (NINDS)
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]
     [phone]

     The Hereditary Disease Foundation
     606 Wilshire Blvd., Suite 504
     Santa Monica, CA  90401
     [phone]

     Huntington Society of Canada
     13 Water Street North, No. 3
     P.O. Box 333
     Cambridge, Ontario NIR 5TB
     Canada
     [phone]

For Genetic Information and Genetic Counseling Referrals:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY  10605
     [phone]

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     [phone]

References

THE MERCK MANUAL 15th ed.:  R. Berkow, et al:  eds; Merck, Sharp & Dohme
Research Laboratories, 1987.  Pp. 1420, 2141.

MENDELIAN INHERITANCE IN MAN, 10th Ed.:  Victor A. McKusick, Editor:
Johns Hopkins University Press, 1992.  Pp. 550-555.

CECIL TEXTBOOK OF MEDICINE, 19th Ed.:  James B. Wyngaarden, and Lloyd H.
Smith, Jr., Editors; W.B. Saunders Co., 1990.  Pp. 2135-2136.

BIRTH DEFECTS ENCYCLOPEDIA, Mary Louise Buyse, M.D., Editor-In-Chief;
Blackwell Scientific Publications, 1990.  Pp. 882-883.

HUNTINGTON DISEASE:  GENETICS AND EPIDEMIOLOGY, P.M. Conneally; American
Journal of Human Genetics (May 1984; 36(3)):  Pp. 506-525.

PROPOSED GENETIC BASIS OF HUNTINGTON'S DISEASE, C.D. Laird; Trends Genet
(Aug 1990; 6(8)):  Pp.242-247.