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$Unique_ID{BRK04296}
$Pretitle{}
$Title{Tuberous Sclerosis}
$Subject{Tuberous Sclerosis Bourneville Pringle Syndrome Epiloia Phakomatosis
TS Tuberose Sclerosis Tuberous Sclerosis-1 TSC1 Sturge-Walker Syndrome
Hypomelanosis of Ito Epidermal Nevus Syndrome}
$Volume{}
$Log{}
Copyright (C) 1984, 1985, 1987, 1988, 1989, 1990, 1992 National
Organization for Rare Disorders, Inc.
35:
Tuberous Sclerosis
** IMPORTANT **
It is possible that the main title of the article (Tuberous Sclerosis) is
not the name you expected. Please check the SYNONYMS listing to find the
alternate name and disorder subdivisions covered by this article.
Synonyms
Bourneville Pringle Syndrome
Epiloia
Phakomatosis
TS
Tuberose Sclerosis
Tuberous Sclerosis-1
TSC1
Information on the following diseases can be found in the Related
Disorders section of this report:
Sturge-Walker Syndrome
Hypomelanosis of Ito
Epidermal Nevus 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.
Tuberous Sclerosis is a rare neurological disorder characterized by
seizures, mental retardation, developmental delay, and skin and eye (ocular)
lesions. Patients may experience a few or all of the symptoms with varying
degrees of severity.
Symptoms
The first symptoms of Tuberous Sclerosis occur during infancy or early
childhood. Approximately 90 percent of patients have seizures as their first
symptom. These episodes of seizures may include muscle spasms (myoclonic
jerks). Brain wave abnormalities can be detected with an
electroencephalograph (hypsarrhythmia). Two-thirds of patients with Tuberous
Sclerosis are mildly or severely mentally retarded.
Benign brain tumors may be detected with computerized tomography (CT
scans), even in the developing fetus.
Between 60 and 90 percent of infants with Tuberous Sclerosis have white
patches or spots (hypomelanotic macules) on their skin at birth. The
characteristic tumors of this disorder (adenoma sebaceum) appear between the
ages of 3 and 5 years. The tumors generally become more numerous during
puberty. Collagen (a white glistening protein) may accumulate in the skin of
the lower back and back of the neck. This may appear as elevated, yellowish-
brown patches with the texture of an orange peel. Small benign tumors
(fibromas) may develop around or under the fingernails and the nail beds
(periungual or subungual). Brown spots (cafe-au-lait macules) and soft
saclike growths (cutaneous nodules) may appear on the skin. About 90 percent
of patients develop tumors in the retina of the eyes (astrocytic hamartomas)
or tumor-like nodules in the brain as well as the skin and eyes (phakomas).
Delayed speech, slow motor development, and learning disabilities may be
associated with Tuberous Sclerosis. Typical behavior patterns include
symptoms resembling childhood autism; episodes of screaming, crying, or rage;
and catatonic rigidity.
Causes
Tuberous Sclerosis is believed to be 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.
The gene that causes this disorder has been located to the long arm of
chromosome 9.
When patients are affected less severely, the cause is thought to be an
unusual, spontaneous genetic change or mutation that is not inherited.
Affected Population
Tuberous Sclerosis occurs in approximately 1 in 20,000 live births and
affects an estimated 10,000 individuals in the United States. Males and
females are affected equally.
Related Disorders
Symptoms of the following disorders can be similar to those of Tuberous
Sclerosis. Comparisons may be useful for a differential diagnosis:
Sturge-Walker Syndrome is a rare disorder that is apparent at birth.
This disorder is characterized by three major symptoms; excessive blood
vessel growth within the membranes that surround the spinal cord
(leptomenigal angiomas); seizures; and accumulation of excessive calcium
within the brain. Generally there is a large birth mark (port wine stain or
nevus flammeus) on one side of the face. The seizures that are common with
this disorder generally increase in frequency as the patient gets older.
Over half of the children with Sturge-Walker Syndrome experience some degree
of mental retardation. (For more information on this disorder, choose
"Sturge-Walker" as your search term in the Rare Disease Database).
Hypomelanosis of Ito is a rare disorder that is characterized by an
unusual lack of skin color (hypopigmentation) affecting many areas of the
body. Other symptoms may include mental retardation, seizures, inability to
sweat in the areas that lack pigmentation, crossed eyes (strabismus),
nearsightedness and a cleft along the edge of the eyeball (coloboma). (For
more information on this disorder, choose "Hypomelanosis of Ito" as your
search term in the Rare Disease Database).
Epidermal Nevus Syndrome is a rare disorder characterized by distinctive
birth marks (nevus) on the skin. Neurological and skeletal abnormalities may
also occur. This disorder is usually apparent at birth and the skin lesions
are most often seen in the mid-face from the forehead down into the nasal
area. Epidermal Nevus Syndrome is often associated with seizures, mental
deficiency, eye problems, bone malformations and atrophy of the brain. (For
more information on this disorder, choose "Epidermal Nevus" as your search
term in the Rare Disease Database).
Therapies: Standard
The treatment for Tuberous Sclerosis is supportive and symptomatic.
Treatment may include the administration of anticonvulsant drugs to control
seizures. Facial tumors (angiofibromas) may be removed using a skin scraping
technique known as derabrasion or with laser treatments. Surgery may become
necessary for certain rapidly growing tumors that might interfere with normal
function. Special education and related services will be helpful for those
children who are mentally retarded.
Conventional anticonvulsants that may be administered include
phenobarbital, phenytoin (Dilantin), clonazepam (Clonopin), valproic acid
(Depakene), carbamazepine (Tegretol), ethosuximide (Zarontin), or
acetazolamide (Diamox). All these anticonvulsants have potential side
effects and require careful monitoring by a physician.
Certain immunizations, such as DPT and Rubella, can prompt seizures in
children with Tuberous Sclerosis. "Infantile spasms" can be treated in some
infants by the use of prednisone or ACTH (adrenocorticotropic hormone).
These medications are used cautiously because of their side effects.
The obstruction of cerebrospinal fluid (CSF) circulation inside the brain
(intracranial hypertension) because of a benign tumor may require a shunting
procedure to drain the liquid or the surgical removal of the tumor. A benign
tumor inside the heart (rhabdomyoma) may not cause symptoms and not require
treatment. Large cystic lesions of the kidneys may also require surgical
decompression or removal, possibly leading to loss of a kidney. If large
groups of enlarged blood vessels (angiolipomas) bleed in the lining of the
abdominal cavity (peritoneum), emergency treatment for shock may be
necessary.
Genetic counseling will be of benefit for patients and their families.
Therapies: Investigational
Investigations into the cause and possible treatments for Tuberous Sclerosis
are ongoing. Blood and skin cells of Tuberous Sclerosis patients have been
banked at the Camden Cell Repository in New Jersey and are available to
researchers around the world. Scientists are trying to develop prenatal
tests and diagnostic blood tests for Tuberous Sclerosis.
This disease entry is based upon medical information available through
October 1992. 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 Tuberous Sclerosis, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
National Tuberous Sclerosis Association, Inc.
8000 Corporate Drive, #120
Landover, MD 20785
(301) 459-9888
(800) 225-NTSA
NIH/National Institute of Neurological Disorders & Stroke (NINDS)
9000 Rockville Pike
Bethesda, MD 20892
(301) 496-5751
(800) 352-9424
For information about seizures:
Epilepsy Foundation of America
1828 "L" Street N.W.
Washington, D.C. 20036
For Genetic Information and Genetic Counseling Referrals:
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. 1630, 2111.
MENDELIAN INHERITANCE IN MAN, 10th Ed.: Victor A. McKusick, Editor:
Johns Hopkins University Press, 1992. Pp. 1116-1118.
CECIL TEXTBOOK OF MEDICINE, 19th Ed.: James B. Wyngaarden, and Lloyd H.
Smith, Jr., Editors; W.B. Saunders Co., 1990. Pp. 2144.
CLINICAL DERMATOLOGY, 2nd Ed.; Thomas P. Habif, M.D., Editor: The C.V.
Mosby Company, 1990. Pp. 654-655.
DISORDERS OF HYPOPIGMENTATION IN CHILDREN, F.J. Pinto; Pediatr Clin North
Am (August 1991; 38(3)): Pp. 991-1017.
NEUROCUTANEOUS SYNDROMES, E.S. Roach; Pediatr Clin North Am (August 1992;
39(4)); Pp. 591-6202.