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$Unique_ID{BRK03811}
$Pretitle{}
$Title{Hemorrhagic Telangiectasia, Hereditary}
$Subject{Hemorrhagic Telangiectasia Hereditary Osler-Weber Rendu Syndrome
Rendu-Osler-Weber Syndrome HHT von Willebrand Disease
Calcinosis-Raynaud-Scleroderma-Telangiectasia Syndrome (CRST) Multiple
Phlebectasias Spider Nevi Cherry Angiomas }
$Volume{}
$Log{}
Copyright (C) 1986, 1988, 1989, National Organization for Rare Disorders, Inc.
285:
Hemorrhagic Telangiectasia, Hereditary
** IMPORTANT **
It is possible the main title of the article (Hereditary Hemorrahagic
Telangiectasia) is not the name you expected. Please check the SYNONYMS
listing to find the alternate names and disorder subdivisions covered by
this article.
Synonyms
Osler-Weber Rendu Syndrome
Rendu-Osler-Weber Syndrome
HHT
Information on the following diseases can be found in the Related
Disorders section of this report:
von Willebrand Disease
Calcinosis-Raynaud-Scleroderma-Telangiectasia Syndrome (CRST)
Multiple Phlebectasias
Spider Nevi
Cherry Angiomas
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.
Hereditary Hemorrhagic Telangiectasia (HHT or Osler-Weber-Rendu Syndrome) is a
hereditary disorder characterized by blood vessel lesions (telangiectases) on
the skin, mucous membranes and in many internal organs. Often, patients
exhibit signs of anemia caused by bleeding of the telangiectases.
Symptoms
Individuals with Hereditary Hemorrhagic Telangiectasia develop red-to-violet
lesions usually in the nasal mucous membranes (mucosa) and on the skin. The
cheeks, ears, lips, and tongue are chiefly affected. Lesions also occur in
the gastrointestinal tract and secondarily in other organs including the
lungs, brain, spinal cord and liver. Bleeding can occur spontaneously or as
a result of injury. Bleeding from the nose (epistaxis) and gastrointestinal
tract becomes more severe with age and may lead to chronic anemia. Vein
abnormalities (arteriovenous fistulae) may lead to a bluish discoloration of
the skin (cyanosis), an increase in the number of red blood cells
(polycythemia), clubbed fingers, and sometimes, stroke. While mortality as a
result of this disorder appears to be less than ten percent, Hereditary
Hemorrhagic Telangiectasia can cause many complications especially since it
is often misdiagnosed or undiagnosed. Individuals with the disease and their
families should be closely monitored by as physician familiar with the
disease.
Causes
Hereditary Hemorrhagic Telangiectasia is a hereditary disorder, transferred
as an autosomal dominant trait. (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 dominant disorders,
a single copy of the disease gene (received from either the mother or father)
will be expressed "dominating" the normal gene and resulting in appearance of
the disease. The risk of transmitting the disorder from affected parent to
offspring is 50% for each pregnancy regardless of the sex of the resulting
child.) Symptoms of Hereditary Hemorrhagic Telangiectasia such as blood
vessel lesions (telangiectases) in the lungs, brain, and liver, appear to be
caused by abnormal connections between arteries and veins (arteriovenous
fistulae). Telangiectases occur when the fistulae form to replace
capillaries which normally connect small veins (venules) and small arteries
(arterioles). The absence of intervening capillaries between the venules and
arterioles are responsible for the profuse bleeding of the lesions.
Affected Population
Hereditary Hemorrhagic Telangiectasia can affect people of both sexes and all
ages. The incidence in Europe has been reported to be 1 in 50,000. However,
this might not be an accurate estimate in light of missed or improper
diagnosis.
Related Disorders
Symptoms of the following disorders can be similar to those of Hereditary
Hemorrhagic Telangiectasia. Comparisons may be useful for a differential
diagnosis:
von Willebrand Disease is a hereditary blood clotting disorder
characterized by prolonged bleeding. Blood clotting is slowed due to a
deficiency of the von Willebrand factor protein and factor VIII protein (the
factor VIII complex). Also, platelets do not stick normally, causing
excessively slow clotting time. Increased risk of excessive bleeding
following surgery, dental procedures or injury occurs in patients with this
disorder. With proper treatment and appropriate precautions, few patients
become seriously handicapped by von Willebrand Disease. (For more
information on this disorder, choose "von Willebrand" as your search term in
the Rare Disease Database.)
Caldcinosis-Raynaud-Sclerodactyly-Telangiectasisa Syndrome (CRST) is a
combination of various symptoms, sand is usually due to Scleroderma.
Calcinosis is marked by deposits of calcium salts in focal nodules in various
body tissues other than the connective tissue which supports the various
organs (parenchymatous viscera). Raynaud's Phenomenon involves a spasm of
the arteries in the fingers causing sensations of numbness and cold.
Sclerodactyly (acrosclerosis) is a form of Scleroderma which occurs with
Raynaud's Phenomenon. Telangiectasia is a discolored enlargement of blood
vessels visible in the skin. (For more information, choose "Scleroderma" and
"Raynaud" as your search terms in the Rare Disease Database.
Multiple Phlebectasias refers to enlargement of veins.
Spider Nevi are small abnormally enlarged arteries visible in the skin
with radiating branches resembling the legs of a spider. These arteries
appear to have a dull red color.
Cherry Angiomas (senile hemangiomas) consists of a red papule due to the
weakening of the capillary wall, seen in many people over thirty years of
age. These spots are also known as DeMorgan's or ruby spots.
Therapies: Standard
Treatment of Hereditary Hemorrhagic Telangiectasia) has been mainly concerned
with preventing or stopping bleeding of the telangiectatic lesions and the
removal or blockage of exceptionally large lesions or arteriovenous fistulae.
Cauterization, whether electrical or with laser light, of telangiectases
in the nasal mucosa may be of temporary benefit since new lesions can grow.
Surgical removal of arteriovenous fistulae has been used in the past, but
more recently occlusion by balloon embolotherapy has been found effective in
the treatment of pulmonary arteriovenous fistulae. Nosebleed (epistaxis) can
sometimes be controlled by applying a compress saturated with
vasoconstrictors such as phenylephrine to the ruptured lesion.
Blood transfusions or iron replacement therapy, either orally or by
transfusing iron dextran, have been used to combat anemia.
Gastrointestinal lesions that produce severe hemorrhage may require
surgical removal.
Therapies: Investigational
Estrogen and progesterone therapy have been used experimentally to prevent
bleeding. Recent findings indicate that estrogen is not effective while
progesterone may hold some promise.
This disease entry is based upon medical information available through
June 1988. 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 Hereditary Hemorrhagic Telangiectasia, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
HHT Foundation International Inc.
P.O. Box 8087
New Haven, CT 06530
Dr. Robert I White, Jr.
Yale School of Medicine
Department of Diagnostic Radiology
333 Cedar Street
P.O. Box 3333
New Haven, CT 06510
NIH/National Heart, Lung and Blood Institute
9000 Rockville Pike
Bethesda, MD 20892
(301) 496-4236
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
MERCK MANUAL OF DIAGNOSIS AND THERAPY: Robert Berkow et al., eds.; American
Medical Association, 1982. P. 1119.